Formation of a hyperdiploid karyotype in childhood acute lymphoblastic leukemia. Hyperdiploidy with greater than or equal to 50 chromosomes is a frequent and distinct karyotypic pattern in the malignant cells of children with acute lymphoblastic leukemia. To understand better the mechanism of formation of the hyperdiploid karyotype, we studied 15 patients using 20 DNA probes that detect restriction fragment length polymorphisms. We first examined disomic chromosomes for loss of heterozygosity. Two patients had widespread loss of heterozygosity on all informative disomic chromosomes, and represent cases of near-haploid leukemia in which the chromosomes doubled. One other patient had loss of heterozygosity limited to chromosome 3; in this patient all of seven other informative disomic chromosomes retained heterozygosity. Loss of heterozygosity was not detected in the remaining 12 patients on a total of 87 informative disomic chromosomes. We then examined tetrasomic chromosomes for parental dosage. Of the 13 patients in whom widespread loss of heterozygosity was not present, 11 patients had tetrasomy 21; 10 of 11 (91%) had an equal dose of maternal and paternal alleles on chromosome 21 and only 1 of 11 (9%) had an unequal dose of parental alleles in a 3:1 ratio. These results suggest that the hyperdiploid karyotype usually arises by simultaneous gain of chromosomes from a diploid karyotype during a single abnormal cell division, and occasionally by doubling of chromosomes from a near-haploid karyotype. The hyperdiploidy in cases without widespread loss of heterozygosity is not caused by stepwise or sequential gains from a diploid karyotype or by losses from a tetraploid karyotype; the former should result in a 3:1 parental dosage for 67% of tetrasomic chromosomes (9% observed) and the latter should result in loss of heterozygosity for 33% of disomic chromosomes (1% observed). Additional studies of the molecular basis for this leukemia subtype are warranted.


A young female case of polyarteritis nodosa strongly suspected by typical angiographic findings which improved rapidly after prednisolone and cyclophosphamide therapy. A 16-year-old girl was admitted with the complaints of headache, chest pain, low abdominal pain and left hemi-numbness. Her blood pressure was high and plasma renin activity and aldosterone levels were elevated. Renal angiography revealed vascular stenoses and microaneurysms although the renal artery and its main branches were not involved. Polyarteritis nodosa (PN) was strongly suspected and oral prednisolone and intravenous pulse therapy of cyclophosphamide were started. The second renal angiography which was performed 11 days after the therapy was started, showed marked improvement of vascular lesions. This is a case which suggests that the angiographic findings of PN can improve very rapidly with therapy.


Tyrosine hydroxylase expression in non-catecholaminergic cells in cerebellar cultures. Organotypic cerebellar cultures, some with incorporated portions of brainstem, were immunostained after 12-19 days in vitro with three different antibodies to tyrosine hydroxylase. Similar cultures were reacted with glyoxylic acid and examined for catecholamine histofluorescence. Locus coeruleus and other subcortical neurons were positive for tyrosine hydroxylase, as were Purkinje cells and outgrowth zone astrocytes. By contrast, only locus coeruleus neurons and their axons exhibited catecholamine histofluorescence after reaction with glyoxylic acid. These results confirm previously reported in vivo developmental studies indicating that tyrosine hydroxylase can be expressed in the absence of its normal biosynthetic products, and suggest that tyrosine hydroxylase cannot be considered to be a specific marker for catecholaminergic neurons in vitro, as well as during development in vivo.


Glutamate, NMDA and NMDA receptor antagonists: cardiovascular effects of intrathecal administration in the rat. Selected excitatory amino acids and antagonists were tested for their effects on arterial pressure and heart rate when administered intrathecally at the second (T2) or ninth (T9) thoracic spinal levels in urethane-anesthetized Sprague-Dawley rats with spontaneous or artificial respiration. Intrathecal administration of glutamate (1 mumol) and N-methyl-D-aspartic acid (NMDA; 2 nmol) at T9 increased arterial pressure and heart rate. The response began within 1 min, peaked at 2-3 min and persisted for 8-15 min. The maximum changes were 20-25 mm Hg for arterial pressure and 40-50 beats/min for heart rate. These responses were prevented by systemic administration of hexamethonium (10 mg/kg). Responses to administration of NMDA at the two spinal levels were essentially the same. Effects elicited by NMDA but not by glutamate were blocked by pretreatment with the NMDA receptor antagonists, D,L-2-amino-5-phosphonovaleric acid (APV; 10 nmol, intrathecal administration) and ketamine (7 mg/kg, i.v.). Intrathecal administration of APV (10, 50 and 200 nmol) at T2 produced dose-dependent decreases in arterial pressure without changing heart rate. The results support the hypothesis that NMDA receptors are involved in regulation of sympathetic output at the spinal level. They also indicate that in this preparation there is a tonic activation of NMDA receptors in sympathetic pathways to the vessels but not to the heart. Finally, the persistence of the response to glutamate in the presence of NMDA receptor antagonists suggests the involvement of non-NMDA receptors in spinal control of sympathetic output.


The development and characterization of a natural killer cell-resistant human renal cell carcinoma cell line. Natural killer (NK) cells are large granular lymphocytes that are able to recognize and lyse a broad spectrum of transformed cells. We report one approach to identify NK surface recognition molecules on human tumor targets. A cloned renal cell carcinoma (RCC) cell line, 5117GB, sensitive to NK activity, was made NK-resistant (5117GBT) by exposure to peripheral blood mononuclear cells. Both cell lines were found to be sensitive to lymphokine-activated killer cells. Both 5117GB and 5117GBT were positive for laminin (25-33%), CD2 (LFA-3 receptor, 95-98%), CD54 (ICAM-1, 99-100%) and CD58 (LFA-3, 100%). 5117GB was positive for HLA-ABC while 5117GBT lost detectable HLA-ABC. F(ab')2 fragments of HLA-ABC were not able to block NK-mediated cytotoxicity of 5117GB. We identified 6 murine monoclonal antibodies that preferentially bind either to sensitive or resistant RCC cells. The role of each of the antigens recognized by these antibodies in NK-mediated lysis is being explored. The development of NK-sensitive and NK-resistant human solid tumor cell lines may allow further exploration of surface molecules involved with NK binding and lysis.


Peptides for calling? An immunohistochemical study of the avian n. intercollicularis. We used two phylogenetically distant avian species (dark-eyed junco, hyemalis, Passeriformes; domestic pigeon, Columba livia, Columbiformes) to determine the immunocytochemical distribution of opioid (leucine-enkephalin, dynorphin B) and non-opioid (adrenocorticotropic hormone) peptides in the n. intercollicularis (ICo), a midbrain region which plays a central role in the control of vocalizations. We found that, in both species, the peptides under study are present as fibers and terminal-like structures, and are similarly distributed. The n. dorsomedialis intercollicularis division contains much less immunoreactivity than the rest of the ICo. Based on this and previous studies, we propose that opioid peptides, possibly transported from the preoptic and hypothalamic regions of the diencephalon to the ICo, regulate vocal behavior by altering respiratory function rather than syringeal mechanisms.


The non-NMDA antagonists, NBQX and GYKI 52466, protect against cortical and striatal cell loss following transient global ischaemia in the rat. The cerebroprotective action of non-NMDA receptor blockade has been assessed in a model of transient global ischaemia using NBQX, 2,3-dihydro-6-nitro-7-sulphamoyl-benzo(F)quinoxaline, and GYKI 52466, 1-(amino-phenyl)-4-methyl-7,8-methylendioxy-5H-2,3-benzodiazepine. HCl. In Wistar rats, prior cauterisation of the vertebral arteries was followed by occlusion of the common carotid arteries for 20 min, with a 7 day survival period before histological evaluation. NBQX, 40 mg/kg, or GYKI 52466, 40 mg/kg, was administered intravenously starting directly after the end of carotid occlusion and ending 3 h later. Both compounds produced significant protection against selective cell loss in the striatum and cortex. Less consistent changes were seen in the hippocampus; protection by NBQX was significant in CA3 but neither compound produced significant protection in CA1. This pattern of protection is interpreted in terms of a blockade of glutamate's action at non-NMDA receptors limited to the initial 3 h of reperfusion.


C-terminal tail of beta-adrenergic receptors: immunocytochemical localization within astrocytes and their relation to catecholaminergic neurons in N. tractus solitarii and area postrema. beta-Adrenergic receptors (beta AR) in the medial nuclei of tractus solitarii (m-NTS) and area postrema (AP) may bind to catecholamines released from neurons, whereas only the AP has fenestrated capillaries allowing access to circulating catecholamines. Since varied autonomic responses are seen following beta AR activation of the dorsal vagal complex, including the m-NTS and AP, we hypothesized that there might be a cellular basis for varied responses to beta AR stimulation that depends on the differential access to circulating catecholamines. Therefore, we comparatively examined the ultrastructural localization of the beta AR in relation to catecholaminergic neurons in these regions. An antibody directed against the C-terminal tail (amino acids 404-418) of hamster beta-adrenergic receptor (beta AR404) was used in this study. The localization of beta AR404 was achieved by the avidin-biotin peroxidase complex (ABC) technique in combination with a pre-embed immunogold labeling method to localize tyrosine hydroxylase (TH), the catecholamine-synthesizing enzyme. Within m-NTS and at subpostremal border, labeling for beta AR404 was evident along the intracellular surface of plasma membranes of small, apparently distal, astrocytic processes. Astrocytic processes with beta AR404-immunoreactivity formed multiple, thin lamellae around TH-labeled and non-TH neuronal cell bodies and dendrites. beta AR404-immunoreactive astrocytes also extended end-feet around blood vessels and surrounded groups of axon terminals that were directly juxtaposed to each other. Some, but not all, of these axons demonstrated TH-immunoreactivity. Fewer beta AR404-immunoreactive astrocytes were detected in AP, regardless of their proximity to catecholaminergic processes or blood vessels. The present astrocytic localization of beta AR404, together with the earlier, neuronal localization of beta AR's third intracellular loop, suggest that the beta AR may be substantially different between neurons and astrocytes. The regional difference in the prevalence of beta AR404-immunoreactive astrocytes suggests that these receptive sites may either: (i) be preferentially activated by catecholamines released from terminals rather than circulating catecholamines; or (ii) be down-regulated in AP due to blood-born substances, such as catecholamines. The extensive localization of beta AR in the border between m-NTS and AP also suggests that catecholaminergic activation of these astrocytes may dictate the degree of diffusion of catecholamines which are of neuronal or vascular origin. The specific localization of beta AR404-immunoreactivity to the more distal portions of astrocytes suggests the possibility that astrocytes have restrictive distributions of beta AR and that the beta-adrenergic activation lead to morphological or chemical changes that are also localized to the distal portions of astrocytes.(ABSTRACT TRUNCATED AT 400 WORDS)


The influence of opioids on local cerebral glucose utilization in the newborn pig. Topical methionine enkephalin, leucine enkephalin, and dynorphin (10(-6)M) previously have been observed to produce prominent pial arteriolar dilation. Dilation to these opioids could be caused directly by opioids acting on vascular receptors, or indirectly, as a consequence of increased metabolism. Therefore, we examined this possibility by determining the influence of opioids on cerebral glucose utilization in piglets with closed cranial windows using the [14C]deoxyglucose method. Qualitatively, the autoradiographic images expressed as a change in relative optical density from vehicle were unchanged by these opioids. Quantitatively, the opioids similarly had no effect on cerebral glucose utilization (53 +/- 5, 70 +/- 8, 63 +/- 5, and 52 +/- 3, mumol.100 g-1.min-1 for vehicle, methionine enkephalin, leucine enkephalin, and dynorphin, respectively). In contrast, topical glutamate (10(-3) M) produced similar dilation but increased cerebral glucose utilization (41 +/- 3 vs 89 +/- 8 mumol.100 g-1.min-1 for vehicle and glutamate, respectively). Therefore, these opioids do not appear to produce vascular effects through a change in cerebral metabolic utilization of glucose.


Hypothalamic corticotropin-releasing hormone and opioid peptide neurons: functional changes after adrenalectomy and/or castration. The influences of short- and long-term castration and adrenalectomy (or both) upon corticotropin-releasing hormone (CRH) mRNA levels, CRH peptide levels, and endogenous opioid peptide (EOP) content in the hypothalamus, and basal and CRH-stimulated EOP release in vitro, were examined. Gonadal and adrenal steroids regulated the function of these hypothalamic peptidergic systems in terms of peptide synthesis, storage pools, and secretion. The steroids were also found to alter the sensitivity of EOPergic neurons to CRH. In some cases, evidence was obtained for an interaction between gonadal and adrenal steroids in determining neuronal function (seen as additive or counteractive effects). A finding of major importance was that the response of these peptidergic systems was markedly influenced by the duration of steroid deprivation, the results of chronic treatment often being opposite to those of acute treatment. Lastly, inspection of the data on peptide synthesis, storage and release, revealed that there was no simple relationship between these three parameters even within a single type of peptidergic neuron.


Anticonvulsants inhibit rat neuronal somatostatin release. Somatostatin (SRIF), a peptide widely distributed in the central nervous system, has been implicated in the genesis of seizure activity in a number of animal models of epilepsy. We examined the effects of the anticonvulsants, phenytoin, carbamazepine and diazepam, on the release of SRIF from dispersed adult rat neuronal cells in short-term culture. Each of these agents caused dose-dependent inhibition of ouabain-stimulated SRIF release in a well-characterized hypothalamic dispersed cell system. We also examined the effects of phenytoin on SRIF release from dispersed rat cortical cells and inhibition of stimulated SRIF secretion was again observed. These findings support the hypothesis that the inhibition of neuronal SRIF release may represent a pharmacological mechanism of action of anticonvulsants.


Role of N-methyl-D-aspartate receptors in dopamine D1-, but not D2-, mediated changes in striatal and accumbens neurotensin systems. The role of N-methyl-D-aspartate (NMDA) receptors in specific D1 and D2 regulation of striatal and accumbens neurotensin (NT) systems was investigated. As demonstrated previously, stimulation of D1 receptors with multiple administrations of SKF 38393 significantly increased striatal and accumbens NT content to approximately 145% of control. These responses were completely blocked by coadministration of the non-competitive NMDA antagonist, MK 801. Previous studies have documented that D2 receptors tonically regulate striatal NT systems. Thus, multiple doses of sulpiride, a D2 antagonist, increased striatal NT content to 167% of control while quinpirole, a D2 agonist, decreased striatal NT content to 58% of control. MK 801 did not alter either striatal NT response to D2 manipulation. As previously reported, levels of accumbens NT changed only in response to D2 blockade and not to D2 stimulation. Thus, sulpiride increased accumbens NT content to 138% of control; this was not blocked by the coadministration of MK 801. NT content also significantly increased after stimulation of glutamate receptors with NMDA. To determine if D1 receptors participate in this NMDA-mediated change, the D1 antagonist SCH 23390 was coadministered. Blockade of D1 receptors did not significantly alter the response of striatal NT systems to NMDA. However, in both striatum and nucleus accumbens, the NMDA effect on NT systems appeared to be lessened. In summary, expression of D1-, but not D2-mediated changes in striatal and accumbens NT systems are markedly dependent on NMDA receptor activity. In comparison, expression of the NMDA-mediated changes in the same NT systems do not appear to be as dependent on D1 receptor activity.


Effects of chronic treatment with selective agonists on the subtypes of dopamine receptors. The effects of chronic administration of selective dopaminergic agonists on D1 and D2 receptor density, affinity and function were measured in Sprague-Dawley rats. Animals received daily injections (i.p.) of the D1-selective agonist SKF-38393 (10 mg/kg), the D2-selective agonist quinpirole (1 mg/kg), SKF-38393 plus quinpirole, or saline for 14 days. Quantitative autoradiographic analysis revealed that the density of D2 receptors was decreased following chronic treatment with quinpirole alone or in combination with SKF-38393 whereas SKF-38393 by itself had no effect on this receptor. In contrast, the density of D1 receptors was increased following treatment with SKF-38393. Although quinpirole by itself had no effect on D1 receptors, co-administration with SKF-38393 attenuated the up-regulation of D1 receptors produced by SKF-38393 in the caudate-putamen and nucleus accumbens but not in the substantia nigra. The up-regulation of D1 receptors in response to chronic SKF-38393 may be attributed to the partial agonist properties of SKF-38393 which may not provide sufficient D1 receptor stimulation to down-regulate the receptor. Quinpirole-induced hypothermia and SKF-38393-induced hyperthermia were measured before and after chronic agonist treatments to examine the effects of these treatments on thermoregulatory functions mediated by each receptor subtype. Treatment with quinpirole or quinpirole plus SKF-38393 resulted in desensitization of quinpirole-induced hypothermia, whereas treatment with SKF-38393 alone had no effect. All of the chronic treatments produced sensitization of SKF-38393-induced hyperthermia. Since not all treatments result in an increase in the density of D1 receptors, up-regulation of D1 receptors is not the sole mechanism for this sensitization.


Inhibition of excitatory amino acid-stimulated phosphoinositide hydrolysis in rat hippocampus by L-aspartate-beta-hydroxamate. The effect of a series of glutamate uptake inhibitors was tested on ibotenate-stimulated phosphoinositide hydrolysis. The pharmacological profile of the inhibitory effect of these compounds on the ibotenate response was quite different from that on glutamate uptake. Aspartate-beta-hydroxamate was the most potent compound with the L-isomer (IC50 11 +/- 2 microM) being considerably more potent than the D-isomer (IC50 104 +/- 12 microM). The effect of the L-aspartate-beta-hydroxamate was found to be specific for ibotenate and quisqualate-stimulated phosphoinositide hydrolysis; this compound did not affect hydrolysis stimulated by carbachol, K+ or sodium fluoride. The inhibition of the ibotenate response was found to involve a non-competitive and irreversible mechanism.


The antidepressants fluoxetine, idazoxan and phenelzine alter corticotropin-releasing hormone and tyrosine hydroxylase mRNA levels in rat brain: therapeutic implications. Various classes of antidepressant drugs with distinct pharmacologic actions are differentially effective in the treatment of classic melancholic depression--characterized by pathological hyperarousal and atypical depression--associated with lethargy, hypersomnia, and hyperphagia. All antidepressant agents exert their therapeutic efficacy only after prolonged administration. In situ hybridization histochemistry was used to examine in rats the effects of short-term (2 weeks) and long-term (8 weeks) administration of 3 different classes of activating antidepressant drugs which tend to be preferentially effective in treating atypical depressions, on the expression of central nervous system genes thought to be dysregulated in major depression. Daily administration (5 mg/kg, i.p.) of the selective 5-hydroxytryptophan (5-HT) reuptake inhibitor fluoxetine, the selective alpha 2-adrenergic receptor antagonist idazoxan, and the nonspecific monoamine oxidase A and B inhibitor phenelzine increased tyrosine hydroxylase mRNA levels by 70-150% in the locus coeruleus after 2 weeks of drug and by 71-115% after 8 weeks. The 3 drugs decreased corticotropin-releasing hormone mRNA levels by 30-48% in the paraventricular nucleus of the hypothalamus. The decreases occurred at 8 weeks but not at 2 weeks. No consistent change in steroid hormone receptor mRNA levels was seen in the hippocampus with the 3 drugs, but fluoxetine and idazoxan increased the level of mineralocorticoid receptor (MR) and glucocorticoid receptor (GR) mRNA, respectively, after 8 weeks of drug administration. Proopiomelanocortin (POMC) mRNA levels in the anterior pituitary and plasma adrenocorticotropic-hormone (ACTH) levels were not altered after 2 or 8 weeks of drug treatment.(ABSTRACT TRUNCATED AT 250 WORDS)


Hippocampal neuronal responsiveness to NMDA agonists and antagonists in the adult rat neonatally treated with MK-801. Long-lasting effects of neonatal interference with N-methyl-D-aspartate (NMDA) receptors were investigated by measuring responses to micro-iontophoretically applied NMDA agonists/antagonist in hippocampal neurons of the adult rat. Rat pups were chronically treated with MK-801 from postnatal day 8 through 19 and tested at postnatal day 70-100. CA1 cell responses to glutamate were not affected by the neonatal treatment. However, a stronger suppression of the NMDA evoked response by the NMDA site antagonist amino-5-phosphonovalerate (APV) was measured, suggesting a long-lasting configurational change of the NMDA receptor. The NMDA evoked responses were equally strong suppressed by MK-801 in both groups, suggesting that channel sites were not affected by this treatment.


A dose-dependent increase of Tau immunostaining is produced by glutamate toxicity in primary neuronal cultures. Neuronal degeneration was produced in primary cultures by glutamate exposure and the modifications of Tau immunoreactivity were analysed in degenerating neurons. After 8-12 days of culture, glutamate was applied at different concentrations (50, 100, 200 and 500 mumol) in a Na(+)- and Mg(2+)-free solution containing calcium. Prior to and 12 hours after glutamate exposure cell death was defined by cell counting in each dish. After fixation, neurons were processed for immunocytochemistry using a Tau2 monoclonal antibody and a Tau polyclonal antibody (Sigma). Tau immunostaining was scored by a blind count of immunoreactive cells and a semi-quantitative evaluation. The results show that the number of labelled neurons and the magnitude of neuronal immunolabelling are both related to the glutamate concentration. Our findings indicate that glutamate induces a dose-dependent increase of Tau immunoreactivity directly related to its cellular action on neuronal cells.


Presynaptic site of action underlying the ethanol-induced inhibition of norepinephrine release evoked by stimulation of N-methyl-D-aspartate (NMDA) receptors in rat cerebral cortex. Rat brain cortex synaptosomes pre-incubated with [3H]norepinephrine were used (1) to provide evidence that part of the NMDA receptors mediating stimulation of norepinephrine (NE) release are located on the noradrenergic varicosities themselves, (2) to characterize these receptors and (3) to examine whether ethanol specifically inhibits the NMDA-evoked NE release via a presynaptic site of action. In synaptosomes superfused with Mg(2+)-free Krebs-Henseleit solution, NMDA (2-min exposure) stimulated tritium overflow in a concentration- and glycine-dependent manner. The stimulatory effect of NMDA was not altered by tetrodotoxin but was abolished by omission of Ca2+ from the superfusion fluid and was considerably reduced in the presence of 1.2 mM Mg2+. DL-(E)-2-Amino-4-methyl-5-phosphono-3-pentanoic acid (CGP 37849; a competitive NMDA receptor antagonist) produced a parallel shift of the concentration-response curve for NMDA to the right, whereas dizocilpine (MK-801; an antagonist at the phencyclidine, PCP, recognition site of the NMDA-gated ion channel) reduced the maximum effect of NMDA. Ethanol inhibited the NMDA-evoked tritium overflow in a concentration-dependent manner. In contrast, in synaptosomes superfused with Ca(2+)-free Krebs-Henseleit solution containing 15 mM K+ throughout, ethanol did not affect the tritium overflow evoked by 2 min introduction of 75 microM Ca2+ into the superfusion fluid. This Ca(2+)-evoked overflow was also not altered by tetrodotoxin and dizocilpine, but was inhibited by the inorganic Ca2+ channel antagonist Cd2+.(ABSTRACT TRUNCATED AT 250 WORDS)


Capsaicin-sensitive nonadrenergic and noncholinergic depressor response to spinal cord stimulation in the pithed rat. The effects of capsaicin on nonadrenergic, noncholinergic depressor responses to spinal cord stimulation were studied in pithed rats. Mean blood pressure (MBP was maintained at a level of 100 mmHg by continuous infusion of methoxamine and hexamethonium to block autonomic outflow. Electrical stimulation of the lower thoracic region (T9-12) via a pithing rod produced a frequency (1-8 Hz)-dependent fall in elevated MBP. The depressor response was abolished by tetrodotoxin, whereas atropine, propranolol, and cimetidine plus pyrilamine did not affect the response. Capsaicin treatment abolished the depressor response. These results suggest that spinal cord stimulation causes neurogenic vasodilation which is mediated by capsaicin-sensitive nonadrenergic and noncholinergic vasodilator nerves.


Carbachol-induced theta-like activity in entorhinal cortex slices. The present study was conducted for two purposes: the first was to evaluate whether activation of cholinergic receptors of the entorhinal cortex in vitro (complete deafferentation) with carbachol (100 microM) was capable of producing theta (theta)-like slow activity. The second purpose was to determine whether carbachol-induced slow waveforms were mediated by muscarinic or nicotinic receptors. We demonstrated that carbachol was capable of producing theta-like slow activity. This activity was not altered by nicotinic antagonists, (+)-tubocurarine and hexametonium. Atropine and scopolamine, in contrast, completely blocked in vitro induced slow waves, indicating entorhinal muscarinic receptors to be actively involved in the mechanism generating cholinergic theta rhythm.


Presynaptic GABAB receptor activation attenuates synaptic transmission to rat sympathetic preganglionic neurons in vitro. Intracellular recordings were made from sympathetic preganglionic neurons (SPNs) in transverse neonate rat spinal cord slices. Superfusion of gamma-aminobutyric acid (GABA; 25-100 microM) or (-)-baclofen (1-30 microM) consistently attenuated the excitatory postsynaptic potentials (EPSPs) evoked by stimulation of dorsal rootlets or lateral funiculus, without causing a significant change of the resting membrane potential and input resistance of the SPNs or of the depolarizations induced by pressure applications of glutamate; the IC50 for baclofen was 2.5 microM. When superfused at a higher concentration (greater than or equal to 500 microM) or ejected by pressure GABA caused a bicuculline-sensitive membrane hyperpolarization. The enantiomer (+)-baclofen (10-50 microM) and the GABAA agonist muscimol (1-10 microM) had no significant effect on the EPSPs. The GABAB receptor antagonist 2-hydroxy-saclofen caused a 10 fold rightward shift of the baclofen dose-response curve, whereas the GABAA receptor antagonist bicuculline (10-50 microM) was ineffective. Glycine had no significant effects on the EPSPs in the concentrations (10-100 microM) tested here. The results indicate that of the two putative inhibitory transmitters in the spinal cord GABA but not glycine depresses EPSPs evoked in the rat SPNs by acting on presynaptic GABAB receptors, the activation of which results in a reduction of excitatory transmitter release.


A population-wide profile of prescription drug use in Saskatchewan, 1989. To measure the prevalence of prescription drug use in Saskatchewan in 1989. Retrospective study. A total of 961,203 Saskatchewan residents (including those who died or were born during the study year) who were eligible for coverage under the Saskatchewan Prescription Drug Plan. The study population represented 94% of the province's total population; those excluded were mostly status Indians (for whom a federal plan is available). At least one prescription was received by 66.0% of the study population in 1989. The mean number of prescriptions per patient was 8.2, and the mean cost of drug material per prescription was $13.95. Females received substantially more prescriptions than males; the difference was particularly notable for cardiovascular agents, antidepressants and benzodiazepines. In the senior population 80.8% received at least one prescription; the mean number of prescriptions per patient was 18.4. The most commonly dispensed drug for the entire study population was amoxicillin (290 prescriptions per 1000 people); triazolam was the most frequently dispensed central nervous system drug (74 prescriptions per 1000 people). Regional variation in overall drug use was remarkably small, although it increased at the drug-class level, especially for tranquillizers. The use of cardiovascular drugs was 27% to 32% higher (depending on how use was measured) per Regina resident than per Saskatoon resident. Benzodiazepines were commonly used on a long-term basis, despite recommendations to the contrary. The results quantify the prevalence of prescription drug use, underscore the importance of careful management of drug therapy by physicians and pharmacists (especially for seniors), illustrate substantial variation in drug therapy strategies and raise questions about utilization of benzodiazepines and cardiovascular drugs.


Reversal of vinblastine resistance by a new staurosporine derivative, NA-382, in P388/ADR cells. Activities of a newly synthesized compound, N-ethoxycarbonyl-7-oxo-staurosporine (NA-382), on cyclic AMP-dependent protein kinase (A-kinase), Ca2+/phospholipid dependent protein kinase (C-kinase), and drug resistance were investigated and compared with those of staurosporine. Protein kinase-inhibitory activity of NA-382 was lower but more selective to C-kinase than that of staurosporine. NA-382 was less toxic to P388 cells and at a non-cytotoxic concentration completely reversed the vinblastine (VBL) resistance of Adriamycin-resistant P388 (P388/ADR) cells without influence on the effect of VBL on the parental P388/S cells. However, the cytotoxicity of staurosporine was too high to give the combination effect with VBL. NA-382 dose-dependently increased VBL-accumulation and inhibited VBL-efflux in P388/ADR with higher potency than staurosporine. Both compounds inhibited the photolabeling of [3H]azidopine on 140-kDa P-glycoprotein in the plasma membrane from the resistant cells. These results suggest that a staurosporine analog, NA-382, reverses multidrug resistance by inhibiting the drug-efflux system or P-glycoprotein.


Effect of the elastase inhibitor eglin C in porcine endotoxin shock. We wanted to demonstrate that the neutrophil elastase inhibitor eglin C reduces the loss of intravascular protein in endotoxin (LPS) shock and that effective concentrations are present in lymph. We used 45 anesthetized miniature pigs in a randomized, controlled trial. LPS 10 micrograms/kg/hr was given for 6 hr. Recombinant eglin C was given before LPS (250 nmol/kg) and continuously at 250 nmol/kg/hr (n = 18); septic controls received saline (n = 18); nine nonseptic controls were used. Eglin C significantly reduced the loss of intravascular protein (plasma volume times plasma protein concentration) from -0.79 g/kg in septic controls to 0.42 g/kg in eglin C-treated animals and reduced plasma concentration of neutrophil elastase, bound to the leukocyte neutral protease inhibitor (LNPI), but systemic hypotension was unchanged. Six additional pigs were anesthetized, prepared with a thoracic lymph fistula, and received eglin C at 475 nmol/kg/hr; three received saline; three received LPS. Eglin C concentrations in lymph were comparable to those in plasma. We conclude that eglin C reduced the loss of intravascular protein during LPS shock and attained effective concentrations in lymph.


The role of interleukin 2 (IL-2) and serum-soluble IL-2 receptor cells in idiopathic IgA nephropathy. Interleukin 2 (IL-2) plays a central role in the immune response and may be involved in the derangement of cellular immunoregulation of idiopathic IgA nephropathy (IgAN). The aim of this study was to investigate the serum levels and production of IL-2 from peripheral blood mononuclear cells (PBMC) and the distribution of IL-2 receptor cells and serum-soluble IL-2 receptor cells (sIL-2R) in patients with IgAN. Twenty-four patients with IgA nephropathy and 11 healthy controls (age and sex matched) were studied during an infection-free period without signs of clinical activity at the moment of the study. Serum IL-2 concentrations did not differ between patients and controls. The supernatant levels of IL-2 taken from 24-hr cultures of PBMC stimulated with phytohemagglutinin or tumor necrosis factor increased significantly in the patients but not in the controls. The percentage of IL-2R positive cells (CD25+) was increased in patients compared with controls. Moreover, IgAN patients had increased activated CD4+ lymphocytes when compared with the controls. Serum levels of sIL-2R were significantly higher in patients than in controls. There were no correlations among renal function, serum IgA levels, and urinary findings with cellular subsets or with IL-2 levels. However, sIL-2R was higher in the subgroup of patients with episodic macrohematuria and was closely related with the presence of red blood cells in the urinary sediment. We conclude that PBMC of IgA nephropathy patients have an overproduction of IL-2 after mitogenic stimulation, an increased helper T cell activity, increased IL-2R+ cells, and elevated serum levels of sIL-2R. These alterations are present in periods of apparent clinical inactivity. Finally, sIL-2R is closely related with hematuria, providing a good marker for disease activity. Our results suggest a pivotal role of IL-2 in cellular immune responses with regard to T cell activation in patients with IgAN.


Attention-deficit hyperactivity disorder in adults. It has been estimated that 30% to 70% of children who are diagnosed as having attention-deficit hyperactivity disorder (ADHD) will continue to show symptoms of the condition as adults. Since the prevalence of ADHD among school children may be 3% or more, its prevalence among adults may be 1% or 2%. The third revised edition of the Diagnostic and Statistical Manual (1987) of the American Psychiatric Association lists three essential features for the diagnosis of ADHD: "developmentally inappropriate inattention, impulsiveness, and hyperactivity." Other conditions associated with ADHD in adults include learning disabilities (or their sequelae), general anxiety disorder, drug and alcohol abuse, and dysthymic and cyclothymic disorders. Strong correlations have been found between ADHD and oppositional defiant and conduct disorders in children and an increased risk for antisocial disorders in adults. A combination of genetic, biologic, and environmental factors appears to be implicated in the etiology of ADHD. The management of adult ADHD requires a multimodal approach. The patient needs to be informed of the cause of his or her impulsive and often self-destructive behavior. Many patients will have learning difficulties that require evaluation and remediation by specialists in learning disabilities. Psychotherapy can help the patients resolve disturbances in perceptions of self and others and family therapy can address difficulties in the adult's relationships with family members. Pharmacotherapy of adult ADHD includes the use of central nervous system stimulants, such as methylphenidate, dextroamphetamine, and pemoline, of the tricyclic antidepressants imipramine and desimipramine, and of other antihypertensive, analgesic, and antimanic drugs.


Onset of action of loratadine and placebo and other efficacy variables in patients with seasonal allergic rhinitis. In a double-blind study, 185 patients with seasonal allergic rhinitis were randomly assigned to receive 10 mg of loratadine or placebo once daily for three days. On day 1 of treatment, the onset of relief of symptoms within 30 minutes of drug administration was reported by 13% of the loratadine-treated patients and by 4% of the placebo patients (P less than 0.05). At two hours after drug administration, 65% of the loratadine-treated patients and 48% of the placebo patients reported symptom relief. On day 3, the loratadine-treated patients reported a significantly greater relief of symptoms, and according to both physician and patient evaluations, the treatment response was significantly superior in the loratadine-treated than in the placebo patients. The incidence of sedation was 2% in the loratadine group and 1% in the placebo group.


Effect of bunazosin, a selective alpha 1-adrenoceptor blocker, on ischemic myocardium in perfused rat heart. The effects of bunazosin on the ischemic myocardium were investigated in isolated, perfused working rat hearts. Ischemia decreased the pressure-rate product and tissue adenosine triphosphate and creatine phosphate levels. Reperfusion did not restore the pressure-rate product nor the adenosine triphosphate levels completely. Bunazosin (5 x 10(-7) and 5 x 10(-6) mol/L) preserved the levels of adenosine triphosphate and creatine phosphate after 20 minutes of ischemia and increased the extent of recovery of the pressure-rate product during reperfusion. The results suggest that bunazosin protects the myocardium against ischemic damage.


[Loss of catecholaminergic neuron in the hypothalamus of multiple system atrophy]. Autonomic failure is one of the primary clinical features of multiple system atrophy (MSA); while the hypothalamus is thought to be a higher center regulating the autonomic nervous system. In the hypothalamus, catecholamine depletion had been confirmed by neurochemical studies but no marked changes had yet been demonstrated by pathological studies. Using three MSA and three control cases, we evaluated the quantitative changes of catecholamine (CA)-containing neurons in the hypothalamus. As markers of CA neurons, neuromelanin (NM)- and tyrosin hydroxylase (TH)-containing neurons were stained by Fontana-Masson and the immunohistochemical technique alternatively. Serial coronal sections, 10 microns thick, were evaluated every tenth section for NM neurons, while two sections were evaluated for TH neurons. The distributions of NM and TH neurons were almost identical; most of them were clustered in the periventricular and arcuate nuclei. The mean numbers of NM and TH neurons per slice were significantly lower in MSAs than in the controls (T test, p less than 0.01); the former were 21.0, 31.6, and 13.7 in MSAs and 78.4, 54.1, and 84.3 in the controls, while the latter were 1.5, 15.5, and 20.5 in MSAs and 48.0, 62.0, and 50.5 in the controls. The clinico-pathological correlation was suggested by the significant differences in the number of TH neurons between two MSA cases: a case with severe orthostatic hypotension and a case with a milder one. The ratio of TH and NM neurons, as obtained from the adjusted sections, was constant in all MSA cases, and there was a positive statistical correlation, but it altered in each control case.(ABSTRACT TRUNCATED AT 250 WORDS)


[Tyrosine hydroxylase-immunohistochemical study in the midbrain of experimental MPTP parkinsonism]. We have performed tyrosine hydroxylase (TH)-immunohistochemical study in the midbrain of experimental MPTP parkinsonism. Eight female adult crab-eating monkeys (macaca fascicularis) were subjected to the experiment and divided into four groups. In the acute experimental parkinsonism (group A), a daily dose of 1.3 mg/kg MPTP was given intravenously for 7 days. Monkeys in the subacute group B were injected every other day a dose of 1.0 mg/kg MPTP intravenously for 7-14 days. Chronic experimental parkinsonism group C was induced by administration of a dose of 0.5 mg/kg twice a week intravenously for 120 days. Group D served as a control. TH-immunoreactive cells were counted in substantia nigra pars compacta (SNc: consisting of lateral, intermediate, medial regions) and paramedian region of midbrain. The remaining TH-immunoreactive cells in group A,B and C were approximately 65.1%, 46.6% and 32.1% of the control group D. The ratio of TH-immunoreactive cells in the lateral region of group A, B and C was lower than in group D. The TH-immunoreactive ratio in the intermediate and medial region of group B and C was lower than in group D. In the medial region of group C, the TH-immunoreactive ratio was increased than in group B. In the paramedian region of all groups, there was no significant differences in the ratio of TH-immunoreactive cells, but many more TH-immunoreactive nerve fibers were observed in group B and C than in group A and D. From the 90th day after MPTP treatment, monkeys in group C began to show a gradual recovery from the flexed posture and hypokinesia.(ABSTRACT TRUNCATED AT 250 WORDS)


[An autopsy case of spinal subdural abscess in the aged--comparative study with neuroradiological findings]. An 82-year-old woman without previous medical problem noticed vague back pain on December 31, 1989, and was admitted to a hospital because she developed a fever, a rapidly progressive weakness followed by anesthesia of the lower extremities and sphincter disturbance. On myelography and myelo-CT, the spinal cord appeared to be displaced by an extramedullary mass which partially blocked the subdural space at the level of T-9 to L-1. When transferred to our hospital on January 8, 1990, she was febrile and complaining of headache with meningeal signs. Percussion tenderness was present at T-8 to L-1 spinal spinous process. Neurological examination revealed that the patient had mild consciousness clouding, total paraplegia in the legs, sensory disturbance of a partial degree at L-1 to L-3 and totally below L-3, brisk but equal tendon reflexes in the upper extremities, areflexia in the legs with positive bilateral Babinski signs and sphincter disturbance. Otherwise she was neurologically unremarkable. Acute inflammatory reactions were prominent among the laboratory findings on admission. A lumbar tap yielded purulent fluid with more than 170,000 cells/mm3, 5,000 mg/dl of protein, 44 mg/dl of glucose and culture of the fluid isolated Escherichia coli. T1-weighted sagittal MRI disclosed an ill defined mass which showed the same or locally higher with gadopentetate dimeglumine (Gd-DTPA) signal intensity as soft tissue, compressing the spinal cord anteriorly from T-7 to L-3. The lesion was noticed to have a more extensive rostral-caudal extent than was inferred from myelography and myelo-CT.(ABSTRACT TRUNCATED AT 250 WORDS)


Analgesic oral efficacy of tramadol hydrochloride in postoperative pain. Tramadol hydrochloride is a synthetic opiate agonist with a plasma elimination half-life of 5 to 6 hours and peak plasma levels at about 1 1/2 hours. It derives its activity from attachment to the mu-receptor and blockage of norepinephrine reuptake. The purpose of this single-dose, double-blind, placebo-controlled study was to determine the analgesic effectiveness of an oral administration of two dose levels of tramadol hydrochloride (75 or 150 mg) compared with the combination of 650 mg acetaminophen plus 100 mg propoxyphene napsylate in 161 patients with severe postoperative pain after cesarean section. Analgesia was assessed over a 6-hour period. Treatments were compared on the basis of standard scales for pain intensity and relief and a number of derived variables based on these data. A global rating of the study medication was also used to compare treatments. The three active treatments were effective analgesics, statistically superior to placebo for many hourly and summary measures. A dose response was seen between the two tramadol doses, with the 150 mg dose providing significantly greater analgesia over the lower dose. The 75 mg dose of tramadol was generally more effective than the acetaminophen-propoxyphene combination after hour 2, and significantly so for some hourly time points, as well as for the global rating of the medication. The 150 mg dose of tramadol was significantly more effective than the acetaminophen-propoxyphene combination from hour 2 through hour 6 for the sum of pain intensity differences and total pain relief scores, as well as for the global rating of the medication. Tramadol hydrochloride at both dose levels is an effective analgesic agent and at 150 mg is statistically superior to the acetaminophen-propoxyphene combination. No serious adverse effects were observed; however, dizziness was more frequently reported with 150 mg tramadol.


Maturation of the goldfish (Carassius auratus) erythrocyte. 1. Cohorts of [3H]thymidine-labelled erythrocytes were examined over a 42-day period in goldfish (Carassius auratus L.) recovering from phenylhydrazine HCl-induced anemia under normoxic conditions at 20 +/- 1 degree C and maintained with minimal disturbance on a high nutritional plane. 2. As judged by changes in primary and derived hematological variables, maturation required 16-20 days. 3. Similar estimates were obtained using cytomorphic variables obtained by image analysing methods. 4. These suggest that juvenile red cells in this species can be identified on the basis of the following characteristics: major axis less than 9.2 microM; one-sided surface area not greater than approximately 50 microns2; axis ratio greater than 0.774; form factor greater than 0.938. 5. Corresponding values for mature cells are: major axis greater than 11.2 microns; area greater than 68.5 microns2; axis ratio less than 0.716; form factor less than 0.912. 6. These criteria, with values for dividing and karyorrhectic cell numbers, offer a basis for more detailed and dynamic characterization of the erythron during response to environmental variation than has previously been possible.


Localization and soma diameter of rat gluteus medius motoneurons. 1. Retrograde transport of horseradish peroxidase was used to examine the localization and soma diameter of motoneurons innervating the deep (predominance of oxidative fibers) and superficial (predominance of non-oxidative fibers) portions of the gluteus medius muscle in rats. 2. The motoneurons innervating the deep portion were located caudally within the gluteus medius motoneuron pool and had smaller average soma diameter than that of motoneurons innervating the superficial portion. 3. These results suggest that the location of the muscle fibers within the muscle is related to the location of motoneurons within the motoneuron pool, and that the soma diameter of motoneuron innervating oxidative muscle fibers may be smaller than those innervating non-oxidative fibers in the rat.


Taurine flux in chicken erythrocytes.

Taurine flux in chicken erythrocytes. 1. The intracellular taurine concentration in chick erythrocytes increased with age. 2. Erythrocyte taurine influx and efflux rates increased with age. 3. Erythrocyte taurine influx decreased when the extracellular sodium concentration was below normal physiological concentrations. 4. Under hypo-osmotic conditions, taurine efflux from erythrocytes increased. 5. The data suggest that chick erythrocyte taurine metabolism changes during early post-hatch development and that one taurine function may be as an osmoregulator.


Pituitary LH content and plasma LH levels following daily GnRH analogue treatment in male red-winged blackbirds (Agelaius phoeniceus). 1. During the 14-day treatment period, plasma LH levels following GnRH analogue (GnRH-A) injections (10.0 micrograms) were significantly reduced after the 6th and the 14th injection. 2. One day post-treatment, the LH pituitary content was significantly reduced in GnRH-A-treated redwings compared to saline-injected controls. 3. Pituitary LH content was significantly higher in GnRH-A treated birds compared to control birds 14 and 28 days post-treatment and plasma LH levels were similar in both groups. 4. Hypersecretion of LH following GnRH-A injections appears to reduce pituitary LH content, acting as a stimulus for its synthesis. 5. These results suggest a higher LH synthesis and storage in the pituitary gland of the GnRH-A-treated birds compared to the control birds during the post-treatment period.


Water proton ion in leg muscles of crayfish subjected to starvation. 1. Using nuclear magnetic resonance, we studied the relationships of in vivo water to establish the correlation between the degree of starvation and the spin-lattice or spin-spin relaxation times (T1 and T2, respectively) of water protons in the leg muscles of crayfish (Procambarus clarkii). 2. As the period of starvation increased, the water content as a component of body weight increased, and the T1 value was proportional to the increase in water content of the leg muscles of the crayfish. 3. The T2 value increased exponentially in comparison with the T1 value for each corresponding stage. 4. Our studies suggest that the state of the body water resulting from starvation was affected by cellular environmental change.


Dietary vanadium and the oxidative state of hepatic and renal pyridine nucleotides. 1. NAD, NADH, NADP and NADPH were measured in the livers and kidneys of chicks receiving 50 mg vanadium/kg diet. 2. There was no effect of dietary vanadium on the oxidative states of the nucleotides, although the growth rate was decreased. 3. The lack of effect of vanadium on the oxidative status of the nucleotides was ascribed to the low tissue concentration of vanadium.


Effect of clenbuterol on skeletal muscle atrophy in mice induced by the glucocorticoid dexamethasone. 1. The ability of clenbuterol to antagonize the catabolic effect of the glucocorticoid dexamethasone on the skeletal muscles, soleus, gastrocnemius and extensor digitorum longus was studied in mice. 2. Daily injections of 5 mg dexamethasone/kg body weight over 10 days caused a significant (20%) loss of muscle weight and protein content in fast twitch but not in slow twitch muscles. 3. Inclusion of clenbuterol (4 mg/kg) in the diet for the period of dexamethasone treatment partly prevented glucocorticoid-induced muscle atrophy, and increasing the concentration of clenbuterol to 8 mg/kg diet totally prevented glucocorticoid-induced protein loss in all muscles.


The effect of glycine administration on taurine concentration in the rat liver. 1. The treatment of rats with glycine (2 mg/g) produced a marked decrease in the hepatic taurine content of neonate rats but not of adult rats. 2. The decrease observed in taurine concentration in the liver of newborn rats was not found in other organs, such as brain or kidney. 3. The results showed that the change in hepatic taurine concentration was dose- and time-dependent, suggesting the existence of an exchange mechanism between taurine and glycine in the rat liver that could participate in regulating the hepatic concentration of these amino acids.


High affinity, Ca2+ specific ATPase and Na+K(+)-ATPase in the gills of a supralittoral crab Leptograpsus variegatus. 1. The gills of Leptograpsus variegatus contain a high-affinity, Ca(2+)-activated ATPase, probably located in the basolateral plasma membrane of the gill epithelia. 2. The affinity of the ATPase for Ca2+ is in the micromolar concentration range (6-35 mumol/l). 3. The specific activity of the enzyme did not change during the moult cycle. The ATPase probably does not contribute substantially to increased calcium influx from the medium during the post moult period. 4. The enzyme is believed to function as a selective extrusion mechanism involved in the maintenance of a low cytosolic Ca2+ level in the epithelial cells.


Fatty liver induced by the addition of excess cystine to a soy-bean protein diet in rats. 1. The effects of excess cystine added to diets with casein, egg protein, soya-bean protein and wheat gluten as protein source on liver and serum lipids of rats were compared. 2. The addition of excess cystine to a soya-bean protein diet produced lipid accumulation in the liver. 3. The addition of excess cystine to casein, egg protein and soya-bean protein diets, but not a wheat gluten diet, increased serum cholesterol.


Blood chemistry of reindeer calves (Rangifer tarandus) during the winter season. 1. Blood characteristics of reindeer calves fed on lichens were studied during the winter. 2. The serum total protein, albumin and globulin concentrations decreased during the winter, obviously partly due to protein deficiency in the diet. 3. High urea levels in autumn and midwinter were possibly reflections of increased stress and/or protein catabolism. 4. Marked lipolysis occurred in late winter, and thus increases were observed in fatty acids, glycerol, triglycerides and acetoacetate concentrations. 5. Serum sorbitol dehydrogenase (SDH) activity increased towards the spring, most probably reflecting changes in the liver. 6. A decrease in serum alkaline phosphatase (AP) activity occurred in midwinter due to cessation of growth. 7. It can be concluded that all the animals were at least in moderate condition throughout the winter and the physiological responses to a negative energy balanced reflected good adaptation.


Long-term effects of dietary monounsaturated and polyunsaturated fatty acids on the lipid composition of erythrocyte membranes in dogs. 1. Lipid analyses were conducted on erythrocyte membranes from dogs fed for 6 months with a normal defatted diet supplemented with either olive or sunflower oil. 2. Levels of palmitic, stearic and arachidonic acids were only slightly affected by dietary fat. 3. The unsaturated fatty acids of n-9 series were elevated in all the phospholipid fractions analysed for olive oil-fed dogs while the n-6 fatty acids, with the exception of arachidonic acid, were elevated in sunflower oil-fed dogs. 4. In the olive oil group the 20:5 (n-3) acid was higher than in the sunflower oil group. 5. The unsaturation index and the cholesterol/phospholipid ratio increased along the time course in the sunflower oil group. Both increases are complementary in order to maintain the constant fluidity of membranes.


Early-life patterns of plasma gut regulatory peptide levels in calves. Effects of age, weaning and feeding. 1. The effects of age, weaning and feeding on the release of seven gut regulatory peptides [gastrin, cholecystokinin (CCK), secretin, vasoactive intestinal peptide (VIP), pancreatic polypeptide (PP), motilin and somatostatin] were studied in calves either exclusively milk-fed between birth and 91 days (P group) or weaned between 22-56 days of age (R group). 2. During the first 3 weeks, the basal plasma immunoreactive levels increased with age for secretin, CCK and PP, decreased for gastrin, motilin and somatostatin and were unaffected for VIP. The changes were particularly rapid for somatostatin and gastrin. After 3 weeks, no significant trend was observed with age in the P group. 3. Weaning resulted in an increase of basal gastrin, CCK, PP and VIP and in a decrease of basal secretin and somatostatin. 4. In the P group, the morning meal was followed 1 hr later by an increase of gastrin and CCK, and by a fall of secretin, PP, motilin and somatostatin, but no significant effect was observed in VIP. Weaning resulted in a reduction of the differences between the fasting and the post-feeding values. 5. These changes suggest a large involvement of endocrine cells in the adaptation of gut tissues, secretions and motility at birth, during the maintenance at the pre-ruminant stage and at weaning.


Dietary arginine requirement of young rainbow trout (Oncorhynchus mykiss). 1. Two growth trials were conducted with young rainbow trout (Oncorhynchus mykiss) to determine the dietary arginine requirement under conditions of rapid weight gain at 15 degrees C. 2. The growth requirement does not exceed 4.2 g arginine/16 g dietary nitrogen and, thus, is much lower than the value of 6.0 g arginine/16 g dietary nitrogen presently listed by the NRC for Chinook salmon and widely applied to all Salmonids. 3. Comparison of the present results with the arginine requirement of the chick reveals remarkable similarity despite the phylogenetic distance between the two species, and demonstrates the need to re-evaluate, as anomalously high, the presently-accepted value for Chinook salmon.


Effects of a beta 2-adrenergic agonist, cimaterol and corticosterone on growth and carcass composition of male rats. 1. Growth rate and carcass composition were measured in rats treated with cimaterol or vehicle only for 21 days, with corticosterone administered during the last 7 days of cimaterol or vehicle only treatment. 2. Cimaterol significantly stimulated the amount of protein in the carcass as well as gastrocnemius and plantaris muscles by 9-15%, and decreased carcass fat by 24%. 3. Corticosterone treatment significantly decreased protein in the carcass and soleus, plantaris and gastrocnemius muscles by 13-33%. 4. The catabolic effects of corticosterone on carcass and muscle protein were reduced by pretreatment with cimaterol, suggesting that beta-adrenergic agonists may have some potential use in preventing muscle wasting during stressed states.


Active and inactive renin in the plasma of the snake Bothrops jararaca. 1. Complementing the work of Gervitz R. K., Hiraichi E., Fichman M. and Lavras A. A. C. Comp. Biochem. Physiol. 86A, 503-507 (1987), conditions have been established for measuring plasma renin activity (PRA) of the venomous snake Bothrops jararaca (Bj). 2. It corresponded to 115.9 +/- 11.5 ng equivalents of angiotensin II (AII) per ml of plasma (N = 13). 3. PRA did not increase when Bj plasma was submitted to acid-cryo-trypsin Bitis arietans venom activation of inactive renin. 4. This may indicate either absence of inactive renin in this plasma or lack of its activation, due to the already demonstrated (Nahas L., Kamiguti A. S., Betti F., Martins I. S. S. and Rodrigues M. I., Comp. Biochem. Physiol. 69A, 739-743, 1981; Prezoto B. C., Hiraichi E., Abdalla F. M. F. and Picarelli Z. P., Comp. Biochem. Physiol. 99C, 135-139, 1991) absence of factor XII.


Redistribution of air within the lungs may potentiate "fright" bradycardia in submerged crocodiles (Crocodylus porosus). 1. Voluntary undisturbed dives by Crocodylus porosus were short in duration (3.08 +/- 1.87 min, mean +/- SD) and accompanied by a small but significant bradycardia (14.3 +/- 5.9% drop). 2. When crocodiles were disturbed underwater there was a rapid onset of "fright" bradycardia, to 65 +/- 6.0% of surface heart rates and dive durations were prolonged to 19.6 +/- 1.8 min. 3. The development of "fright" bradycardia was not accompanied by any increase in intratracheal pressure or expulsion of lung gas. However, sustained contraction of the abdomen and expansion of the thorax revealed a redistribution of air anteriorly within the lungs. 4. We propose that the redistribution of air within the lungs may generate an afferent signal which potentiates the initiation of a severe, dive-prolonging bradycardia.


Major buffering constituents in animal muscle. 1. Among the muscles of six fish species, three mammals, and a bird, white muscle of skipjack tuna showed the highest buffering capacity (BC) in the pH range 6.5-7.5, followed by the muscle of little-piked whale, chicken pectoralis minor, and mackerel white muscle. 2. Contribution of low-molecular weight components to the muscle BC was as high as 48-96%, while the contribution of muscle proteins was below 50%. 3. Histidine-related dipeptides and inorganic phosphate were found to be major buffering constituents in muscle. 4. The dipeptides accounted for the BC differences found between the species and muscle types.


Mesotocin and oxytocin in the brain and plasma of an Australian marsupial, the northern brown bandicoot, Isoodon macrourus. 1. Mesotocin (MT) and oxytocin (OT) were measured in the brain and plasma of bandicoots using reverse phase high performance liquid chromatography and specific radioimmunoassays. 2. MT and OT were found in the pituitary (1.25 +/- 0.10 micrograms/MT; 0.725 +/- 0.077 micrograms/OT) and hypothalamus (38.37 +/- 6.46 ng/MT; 19.1 +/- 4.61 ng/OT). Smaller amounts were present in the cerebral cortex. 3. Basal plasma concentrations ranged from 1.5 to 8.1 pg/ml for both peptides (N = 14) and were elevated by stress. 4. It was concluded that both MT and OT are secreted by the bandicoot brain and that stress stimulates secretion.


Characterization of 2-[125I]iodomelatonin binding sites in the brain of a marsupial, Bennett's wallaby (Macropus rufogriseus rufogriseus). 1. Specific high affinity binding of 2-[125I]iodomelatonin was detected in the brain of the pouch young of a marsupial, Bennett's wallaby. 2. Binding was rapid, stable, saturable and reversible. 3. Scatchard analysis indicated a single class of high affinity binding sites with an equilibrium dissociation constant (Kd) of 68 +/- 13 pM, a maximal number of binding sites (Bmax) of 0.7 +/- 0.1 fmol/mg protein and a Hill coefficient (nH) of 1.12 +/- 0.10. 4. Specific binding was inhibited by GTP (1 mM) indicating that the melatonin receptor is coupled to a guanine nucleotide binding protein, and by melatonin and closely related analogues with a potency order identical to that reported previously in the brain of eutherian mammals, birds and a reptile. 5. These studies suggest that the melatonin receptor is well-conserved through evolution.


In vivo and in vitro protein synthesis of oviducal pars recta by estradiol effect. 1. Proteins secreted by toad oviductal pars recta are involved in fertilization and their biological activity is regulated by estrogens. 2. Effect of 17 beta-estradiol on protein synthesis was examined on castrated animals by different in vivo and in vitro experimental approaches. 3. Different routes of L-[3H]leucine administration were assessed. An intralymphatic route was the most efficient for incorporating radioactivity per mg of trichloroacetic acid insoluble proteins. 4. Ligature of pars recta induces protein synthesis at a similar level to exogenous estradiol. 5. Electrophoretic pattern of radioactive proteins did not show synthesis of a specific protein related to the zone with biological activity. 6. Pars recta releases newly synthesized proteins in vivo into its fluid secretion as much as in vitro into culture medium.


Haematology, red cell metabolism and blood chemistry of the black-faced cormorant Leucocarbo fuscescens. 1. Haematology, red cell metabolism and blood chemistry of five fledgeling black-faced cormorants Leucocarbo fuscescens were studied and the results were compared with previously reported data on several other sea-birds. 2. The mean erythrocyte count of the cormorant is similar to that of penguins but lower than that of flying, non-diving sea-birds. The cormorant's red cell mean cell volume (MCV) is lower than that of penguins but higher than that of non-diving sea-birds. 3. Leucocyte numbers are within expected limits for avian species. 4. Red cell enzymes: glucose phosphate isomerase, phosphofructokinase, aldolase and enolase are higher in the cormorant than in the little penguin; glyceraldehyde phosphate dehydrogenase, monophosphoglyceromutase, pyruvate kinase, lactate dehydrogenase and glutathione reductase are lower. 5. Haemoglobin electrophoresis showed a typical avian haemoglobin pattern.


Coupling between the intracellular pH and the active transport of sodium in an epithelial cell line from Xenopus laevis. 1. The relationship between the rate of active Na+ transport and intracellular pH (pHi, measured as the BCECF fluorescence) was studied in A6 monolayers in the presence of CO2. The total buffering power (beta total) and its components (beta i and beta CO2) were assessed at various pHi. 2. The activity of Na+/H+ and Cl-/HCO3- exchangers were expressed in A6 cells; both antiports were found to participate in pHi homeostasis under standard conditions. 3. Alterations in the rate of Na+ transport induced variations in pHi. 4. Na+ transport rate was a hyperbolic function of external Na+ concentration. The curve was shifted by changing pHi: a mixed inhibition of Na+ transport by pHi was found. 5. The pHi appears as a possible mediator coupling the rate of Na+ transport across the apical and the basolateral membrane in tight epithelia.


Accumulation of radiocalcium from the aquatic medium via the cloaca and bucco-pharynx of Australian freshwater turtles (Chelidae). 1. The cloacal and bucco-pharyngeal regions of three species of Australian freshwater turtles were experimentally compared for their ability to take up radiocalcium directly from the aquatic medium. 2. The cloacal route was at least 4 times more important than the bucco-pharyngeal route for radiocalcium uptake, in each of the three species investigated. 3. Histological examination of anatomical regions in the cloaca showed that the cloacal bursae of three species (E. dentata, C. longicollis and E. signata) had abundant villi and infolded mucosal epithelia that increase the surface area of the epithelium exposed to the aquatic medium. 4. Electron microscopic studies on the mucosal epithelium of the cloacal bursae showed that it contained many structural characteristics indicative of an exchange function and consistent with the cloacal bursae being an important site of radiocalcium uptake within the cloaca.


Changes in myosin and actin filaments in fast skeletal muscle after denervation and self-reinnervation. 1. Myosin and actin filaments of the contractile apparatus of the denervated and self-reinnervated rat leg fast muscle were examined in ultrastructure. In parallel, the total contents of actin and of myosin heavy chains (MHC) were investigated. The results were compared with the corresponding ones in the slow muscle. 2. In the denervated-atrophying fast muscle the myosin filaments disappeared before the actin filaments. However, in contrast to the slow muscle, the local disproportion between the filaments was soon compensated, and their hexagonal arrangement was maintained for about one month after denervation. The contents of MHC and actin decreased, but their ratio remained similar to that in the controls. 3. In the later stage of atrophy the proportion of myosin to actin filaments and the ratio of the corresponding proteins decreased, and the hexagonal arrangement of filaments was disturbed. The denervated fast and slow muscles became similar (in the latter, such changes occurred during the initial weeks after denervation). 4. In the fast muscle recovering after reinnervation (on the third week after denervation) the numbers of myosin and actin filaments, and the contents of the corresponding proteins increased in parallel and the hexagonal arrangement of filaments was maintained (differently than those observed in the slow muscle).


Regional differences for the D-amino acid oxidase-catalysed oxidation of D-methionine in chicken small intestine. 1. Enzymic oxidation of D-[1-14C]methionine (D-met) to 2-keto-4-methylthiobutanoate (KMB) has been determined using 100,000 g supernatants prepared from chicken tissue homogenates. 2. The small intestinal mucosa contains substantial oxidative activity towards D-met, which represents about one-half and one-tenth the hepatic and renal activity, respectively. 3. KMB is poorly decarboxylated and rather transaminated to L-met. 4. The specific activity for D-met oxidation in the duodenal mucosa is 1.5- and 4.0-fold than in the jejunal and ileal mucosa, respectively. 5. The intestinal D-met-oxidizing activity is dramatically altered by the D-amino acid oxidase specific inhibitor benzoate.


Assignment of the chicken tyrosine hydroxylase gene to chromosome 6 by FISH. The gene for tyrosine hydroxylase, the first and rate-limiting enzyme in the biosynthetic pathway of catecholamine neurotransmitters, has been localized in situ to chromosome 6 in the chicken. It is the first DNA marker to be reported for this telocentric macrochromosome. Use of a 45-kb biotinylated chicken-specific cosmid probe and a sensitive fluorescent detection system proved to be highly efficient, with over 90% of metaphases showing positive hybridization signals on one or (usually) both chromosome 6 homologs, in physically mapping this single-gene locus.


Treatment of enterocutaneous and colocutaneous fistulas with early surgery or somatostatin analog. Standard therapy of enterocutaneous (ECF) and colocutaneous (CCF) fistulas consists of "conservative" management, with surgery reserved for failures of maximal medical treatment. We conducted a five-year retrospective review of 28 patients with low-output ECF and CCF to determine the outcome of early surgical and nonsurgical treatment of these conditions. Twelve men and 16 women with a mean age of 60 years presented with 22 ECF and 6 CCF. Six patients had early operative intervention in an attempt to close their fistulas, while the remaining 22 patients were treated without surgery. In addition, four of the nonsurgical group received parenteral somatostatin analog (SA). None of the surgical patients was septic preoperatively (mean WBC = 9.7), the mean preoperative hospital stay was 11 days, and no patients required a proximal diverting stoma. All of the surgical group resumed normal gastrointestinal function within two weeks, and seven of the nine (78 percent) demonstrated no recurrence of the fistula at a mean follow-up of 8.3 months. Of the 22 medically treated patients, three of the four who received SA healed their fistulas within two weeks. Only two of the other 13 medically treated patients (15 percent) healed their fistulas. Early surgery or the use of SA should be considered in the treatment of patients with low-output intestinal fistulas.


[Dental alloys and allergy. Case report]. The case of a 67-year-old woman, who had been wearing an upper partial removable denture with a cast metal framework made of CoCrMo alloy for years without any problems, is described. After the extraction of a molar tooth a nickel alloy retention was soldered to the framework. Following reinsertion allergic reactions appeared. The soldered joint showed considerable corrosion. After removing the retention and the soldered joint, the allergic reactions disappeared, although an epicutanceous test had revealed a positive reaction to cobalt. This case supports the high corrosion resistance and biocompatibility reported for CoCrMo alloys in the literature and the loss of these properties due to inadequate processing. Furthermore, the case illustrates a true allergic reaction. In contrast to the rather indiscriminate use of the term allergy to describe various vague disorders, this diagnosis should be restricted to clearly identified clinical situations.


A trophoblast-specific factor(s) suppresses circulating prolactin levels and increases tyrosine hydroxylase activity in tuberoinfundibular dopaminergic neurons. Rat choriocarcinoma (Rcho) cells, which are morphologically similar to trophoblast giant cells of the normal placenta and produce placental lactogen-I in vivo, were used to investigate placental feedback on PRL secretion and tuberoinfundibular dopaminergic neuronal activity. Rcho cells were injected into female rats either intracerebroventricularly 60-65 h before use or under the kidney capsule 10-14 days before use. The following endocrine conditions were used: 1) ovariectomized rats with or without bromocriptine treatment, 2) immature (40-44 days old) rats, 3) adult cycling (diestrous) rats, and 4) pregnant rats. Serum PRL levels in ovariectomized, diestrous, and immature female rats were suppressed to less than 20% of control levels by secretions from the Rcho cells. Tyrosine hydroxylase (TH) activity in the stalk-median eminence (SME) was increased 2-fold above control activity in Rcho-treated ovariectomized and immature female rats. When TH activity was reduced to 40% of control levels by 50 h of bromocriptine treatment, secretions from Rcho cells increased TH activity 3.5-fold to levels similar to those for Rcho alone. Even though Rcho treatment suppressed PRL levels, TH activity in the SME of cycling (diestrous) rats was not altered after either central (65 h) or peripheral (12 days) administration of cells. TH mRNA levels in the arcuate nuclei were unaltered by Rcho cells in immature female and adult cycling rats. TH mRNA levels in ovariectomized rats were markedly reduced 75% by 50 h of bromocriptine treatment and modestly reduced 33% 65 h after injection of Rcho cells. However, Rcho cells partially reversed the bromocriptine-induced decline in TH mRNA to levels seen for Rcho cells alone. On day 7 of pregnancy, secretions from Rcho cells abolished the nocturnal and diurnal PRL surges characteristic of early pregnancy and suppressed circulating PRL levels throughout the day to less than 20% of intersurge PRL levels. Rcho cells eliminated the semicircadian rhythm in TH activity in the SME, which was out of phase with the twice daily PRL surges of early pregnancy. TH activity was increased by Rcho factor(s) at 0330 h (nocturnal surge) and 1800 h (diurnal surge), but not at 1000 h (intersurge). MMQ cells, pituitary-derived clonal PRL-secreting cells, similarly terminated the biphasic rhythm of PRL release and tuberoinfundibular dopaminergic neuronal activity during early pregnancy.(ABSTRACT TRUNCATED AT 400 WORDS)


Interaction of ethanol with signal transduction mechanisms mediating growth hormone release by rat pituitary cells in vitro. The effects of ethanol on signal transduction mechanisms of rat GH (rGH) release were investigated in primary culture of rat anterior pituitary cells. Ethanol (30, 100, and 300 mM) had no significant effect on basal rGH release or cell content after a 4-h incubation or on intracellular cAMP levels at 30 min. Ethanol did not alter rGRH (10(-11) M)-stimulated rGH release, but at concentrations of 100 and 300 mM it inhibited rGRH (10(-9) M)-stimulated rGH release by 12% (P less than 0.05) and 54% (P less than 0.01). In contrast, a dose-dependent stimulatory effect was observed on rGRH-induced cAMP accumulation. Ethanol enhanced the inhibitory effect of SRIH (10(-11) and 10(-9) M) on rGH release by up to 24% (P less than 0.01). Stimulation of rGH release by cAMP derivatives and forskolin was partially inhibited by ethanol, as was cAMP accumulation after forskolin treatment. Cholera toxin-stimulated rGH release was also inhibited by ethanol, whereas cAMP accumulation was increased. At the higher concentrations, ethanol enhanced rGH release after protein kinase-C activation by phorbol ester and after stimulation of calcium influx with Ca ionophore. No significant ethanol effect was noted on prostaglandin E2-stimulated rGH release, and ethanol did not alter rGH mRNA levels or proliferation of a pituitary somatomammotroph cell line. The results indicate that ethanol exerts multiple effects on systems mediating GH release from the pituitary in vitro. However, the inhibitory influence of ethanol on GH secretion is related primarily to the adenylate cyclase-cAMP pathway, which represents the major signal transducing system in the somatotroph.


Immunocytochemical colocalization of hypothalamic progestin receptors and tyrosine hydroxylase in steroid-treated monkeys. Progesterone (P)-induced PRL secretion in estradiol (E)-primed monkeys is not due to direct pituitary stimulation, because lactotropes do not express progestin receptors (PR). However, the hypothalamus, particularly the tuberoinfundibular dopaminergic system (TIDA), plays a major role in the regulation of PRL secretion. To determine whether hypothalamic dopamine neurons are progestin target cells, the colocalization of PR and tyrosine hydroxylase (TH), a phenotypic marker of dopaminergic neurons, was examined with double immunocytochemistry. Two methods for visualizing the antigens were applied; the first was a dual peroxidase method, and the second was a peroxidase-alkaline phosphatase method. In addition, the question of whether E induces PR in dopamine neurons was explored. Spayed female monkeys were treated with empty Silastic capsules, E-filled capsules for a period of 28 days, or E capsules supplemented with P capsules for the last 14 days of E treatment. Only the E- plus P-treated monkeys exhibited an increase in serum PRL during the P treatment period. Frontal sections at the level of the optic chiasm and arcuate nucleus were examined for the colocalization of TH and PR. After E treatment, hypothalamic PR-positive cells increased in both intensity and number. Neurons expressing both TH and PR were detected in the rostral hypothalamus, lateral to the third ventricle (A11-rostral) and in a discrete subventricular population (A11-subvent). The lateral population continued caudally (A11-caudal). The A11-subvent population exhibited little steroid regulation. Of the remaining A11 TH neurons, approximately 20% exhibited PR in the spayed and E-treated groups. Addition of P doubled the percentage of PR-containing TH neurons in this group. Although very few TH-positive neurons in the ventral arcuate nucleus contained PR (A12-ventral), many double labeled neurons were observed in the dorsal arcuate region (A12-dorsal). Ventral arcuate TIDA neurons were not regulated by steroids, but E plus P increased PR expression in A12-dorsal. Double labeled cells were rarely seen in the zona incerta (A13) or the emerging ventral tegmental area (A10). In summary, P probably does not act directly on ventral arcuate TIDA neurons to stimulate PRL secretion. However, the frequency of PR-positive dopamine neurons in the A11-rostral, A11-caudal, and A12-dorsal groups increased with E and P treatment. Therefore, the contribution of the PR-positive periventricular dopamine neurons to progestin-stimulated PRL secretion may be important.


Single channel analysis of ketamine interaction with a quisqualate receptor. The interactions of the general anaesthetic ketamine with the quisqualate-sensitive L-glutamate receptor (QUIS-R) of locust muscle have been investigated at the single channel level using a M omega seal patch clamp technique. Low concentrations (10(-10) to 10(-9) M) of ketamine did not significantly alter the kinetics of the QUIS-R channel. Higher concentrations of ketamine decreased the probability of the channel being open, the frequency of channel opening and the channel mean open time, and increased the channel mean closed time. Probability density functions of channel dwell times indicate that during application of greater than 10(-8) M ketamine the distribution of channel openings becomes restricted mainly to brief events. These results are consistent with the view that ketamine blocks the open, and possibly also the closed, channel of locust muscle QUIS-R and that this anaesthetic dissociates only slowly from its blocking site(s).


The putative polyamine antagonists ifenprodil and SL 82.0715 enhance dopamine efflux from rat striatal slices independent of NMDA receptor activation. NMDA stimulated the release of endogenous or tritiated dopamine from rat striatal slices and tritiated norepinephrine from cortical and hippocampal slices. The putative polyamine antagonists ifenprodil and SL 82.0715 inhibited [3H]norepinephrine release from cortical and hippocampal slices but enhanced the basal efflux of endogenous and tritiated dopamine from striatal slices. Incubation of striatal slices in a calcium-free buffer did not ameliorate these effects suggesting that the increase in dopamine efflux was not due to a calcium-dependent release process. Superfusion of striatal slices with 10 microM of either ifenprodil, cocaine, or amphetamine resulted in a significant release of tritiated dopamine which was reversed when the slices were again superfused with non-drug-containing buffer. The release observed in the presence of 10 microM ifenprodil (7-fold increase over basal) was intermediate between that observed for cocaine (3-fold increase) and amphetamine (12-fold increase). Both ifenprodil and SL 82.0715 also blocked the uptake of [3H]dopamine into striatal synaptosomes with IC50 values of approximately 1.5 microM. This was again intermediate between the values obtained for cocaine (0.43 microM) and amphetamine (4.2 microM). These results suggest that ifenprodil and its analog SL 82.0715 may act as indirect dopamine agonists by both blocking presynaptic dopamine uptake and by directly increasing the basal efflux of dopamine.


Basic study on the measuring of fatigue by the minimum audible pressure. Nowadays, human senses of vision and hearing receive many stimulations. In particular, VDT work is commonly performed by people of all ages. Therefore, in order to regulate working hours we need to measure the fatigue due to VDT work. The current measuring system depends on the flicker value (CFF). This report describes a new measuring system which depends on the measurement of the fluctuation in the minimum audible pressure (MAP) while using the increase of threshold value as an index of fatigue, and the results of the related experiment. In Test 1, the test sound was set at the pure sound of 1,000 Hz. In Test 2, an ordinary hearing acuity inspection room was used, using the method of limit measurement and headphones (Telephonics, TDH39, MX41/AR). As a result, it was verified that the most suitable rate of increasing and decreasing audible pressure was by 2 dB or 1 dB. It was proved from these tests that the minimum audible pressure could be used satisfactorily as a practical index for absolute measurement of hearing sense fatigue.


A comparison of the selectivities of SCH 23390 with BW737C89 for D1, D2 and 5-HT2 binding sites both in vitro and in vivo. The in vitro affinities (KIs) for SCH 23390 in D1, D2 and 5-HT2 binding assays were 0.4, 631 and 20 nM as compared with 0.3, 79 and 79 nM for BW737C89. The KB values, derived from their abilities to right-shift dopamine-mediated dose-dependent increases in striatal adenylyl cyclase activity, were 0.8 and 0.5 nM for SCH 23390 and BW737C89, respectively. Thus, BW737C89 was a highly potent dopamine D1 receptor antagonist and, although it was less D1/D2-selective than SCH 23390, it was more D1/5-HT2-selective. Both SCH 23390 and BW737C89 (0.1-100 mumol/kg s.c.) exhibited a selective dose-dependent protection of D1, but not D2, binding, from inactivation by N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ, 8 mg/kg s.c.) as measured by [3H]SCH 23390 (D1) and [3H]spiperone (D2) binding. The ED50 values for this selective protection of D1 binding were similar and were between 1 and 3 mumol/kg s.c. BW737C89 showed no protective effect at all on the inactivation of [3H]ketanserin (5-HT2) binding by EEDQ whereas SCH 23390 started to show protection at doses of 10 mumol/kg s.c. and above. A direct comparison of the time course of the effects of pretreatment of a dose of 30 mumol/kg s.c. of both compounds to protect 5-HT2 binding was carried out. This study confirmed the complete lack of protective effect of BW737C89 from 1 to 4 h of pretreatment whereas SCH 23390 exhibited 62, 29 and 28% protection at 1, 2 and 4 h pretreatment respectively.(ABSTRACT TRUNCATED AT 250 WORDS)


The effect of hypercholesterolaemia and atherosclerosis on alpha-adrenoceptor-mediated vasoconstriction in conscious rabbits and rabbit aorta. Rabbits were fed a diet containing 1% cholesterol for 4 or 8 weeks and the constrictor responses to alpha-adrenoceptor agonists, as well as endothelium-dependent and endothelium-independent dilatation, were examined both in vivo and in vitro. The high cholesterol diet caused a significant elevation of plasma cholesterol concentration but no macroscopic evidence of atherosclerosis after 4 weeks whereas after 8 weeks there was a significant development of atherosclerotic lesions in the thoracic and abdominal aorta. In conscious rabbits pressor responses to the non-selective alpha-adrenoceptor agonist noradrenaline and the selective alpha 1-adrenoceptor agonist phenylephrine were enhanced after 4 weeks but returned to control levels after 8 weeks on the diet. The pressor responses to the alpha 2-adrenoceptor agonist B-HT 920 were reduced by the development of atherosclerosis. In the isolated thoracic aorta from these rabbits contractile responses to noradrenaline were impaired by hypercholesterolaemia whereas responses to phenylephrine were unaffected. Endothelium-dependent relaxation was impaired by hypercholesterolaemia both in vivo and in vitro after 4 and 8 weeks on the diet whereas endothelium-independent relaxation was not affected. These results indicate that the effect of hypercholesterolaemia on alpha-adrenoceptor-mediated constriction is dependent on: (1) the absence or presence of atherosclerotic lesions, (2) the size of the artery and (3) the subtype of alpha-adrenoceptor involved in the response. There does not appear to be any relationship between the loss of endothelium-dependent relaxation in hypercholesterolaemia and the observed changes in adrenergic vasoconstriction.


Autoradiographic localization of [3H]quinpirole binding to dopamine D2 and D3 receptors in rat brain. A radiolabelled form of the dopamine agonist, quinpirole (LY17155), has been evaluated as a ligand for dopamine receptors in the rat brain. Quinpirole has been reported to be a selective D2 dopamine agonist; however, a recent report has indicated that it may have high affinity for a novel dopamine binding site which has been termed D3. In rat brain sections, [3H]quinpirole binding exhibited a distribution similar to that described for dopamine D2 receptors using either agonist or antagonist labelling. High densities of binding could be found in caudate-putamen, nucleus accumbens, olfactory tubercle and islands of Calleja. When the labelling was done in the presence of 10 microM guanylyl-5'-imidodiphosphate to convert the dopamine D2 receptor to a 'low affinity agonist conformation', binding was inhibited in most brain regions with the notable exception of the islands of Calleja which retained most of the [3H]quinpirole binding. The guanine nucleotide insensitivity of this binding and distribution of this site indicates that [3H]quinpirole is binding to dopamine D3 receptors in this region of the brain. Therefore, these results indicate that [3H]quinpirole labels a high affinity agonist conformation of dopamine D2 receptors as well as dopamine D3 receptors in rat brain. In addition, this study provides the first detection the dopamine D3 receptor protein in the brain.


Effects of presynaptic alpha-adrenoceptors and neuronal reuptake on noradrenaline overflow and cardiac response. Using an in situ perfused, innervated rat heart model, we studied the effects of presynaptic alpha-adrenergic and neuronal reuptake inhibition on evoked noradrenaline (NA) overflow and the postsynaptic response by sympathetic ganglion stimulation. NA overflow was significantly increased by neuronal reuptake inhibitors (desipramine and (+)-oxaprotiline) or by alpha-adrenoceptor antagonists (phentolamine and yohimbine), but the inotropic response was augmented only by alpha-antagonists. In the presence of desipramine, nerve stimulation induced a frequency-dependent increase in NA overflow and postsynaptic response, both were enhanced by yohimbine. In the absence of desipramine, however, postsynaptic response was potentiated by yohimbine despite an unchanged (at 2 and 5 Hz) or even reduced NA overflow (at 10 Hz). Thus, this study suggests that NA release and cardiac response are modulated by presynaptic alpha-adrenoceptors, and that the neuronal reuptake modifies the amount of NA overflow but has little effect on the postsynaptic response.


Cardiovascular effects of microinjections of quipazine into nuclei of the medulla oblongata in anaesthetized cats: comparison with L-glutamate. Unilateral microinjections of quipazine (0.9 micrograms in 50 nl) into the subretrofacial nucleus produced hypertension and a slight tachycardia associated with an increase in renal sympathetic nerve activity. Microinjections of quipazine lateral, caudal or rostral to this nucleus failed to alter blood pressure and heart rate. Similarly, microinjections of l-glutamate (3 nmol in 15 nl) into the subretrofacial nucleus elicited hypertension, tachycardia and renal sympatho-excitation. The magnitude of the pressor response to quipazine was smaller than the response elicited by l-glutamate but its duration was longer. Microinjections of quipazine into the lateral tegmental field at l-glutamate hypertensive sites failed to alter arterial blood pressure and heart rate. In contrast, microinjections of quipazine into the caudal ventrolateral medulla or into the nucleus tractus solitarii produced hypotension and sympatho-inhibition. These effects were prevented by microinjections of the 5-HT2 receptor antagonists, LY 53857 or BW 501C. The present results indicate that stimulation of 5-HT2 receptors of the subretrofacial nucleus produces hypertension and sympatho-excitation whereas stimulation of 5-HT2 receptors in the caudal ventrolateral medulla and in the nucleus tractus solitarii produces hypotension and sympatho-inhibition.


Investigations of prejunctional alpha 2-adrenoceptors in rat atrium, vas deferens and submandibular gland. We have examined the effects of a series of alpha 2-adrenoceptor antagonists on the stimulation-evoked release of tritium from rat atrium, vas deferens and submandibular gland pre-incubated with [3H]noradrenaline, and correlated these potencies with affinities for the alpha 2A-ligand binding site of human platelet and the alpha 2B-ligand binding site of rat kidney. The alpha 2B-selective adrenoceptor antagonists prazosin and ARC 239 showed significantly higher, and the alpha 2A-selective antagonist BRL 44408 showed significantly lower, potency in atrium than in vas deferens and submandibular gland. Yohimbine and BDF 8933 failed to distinguish between prejunctional alpha 2-adrenoceptors or between ligand binding sites. It is concluded that the prejunctional alpha 2-adrenoceptor of rat atrium resembles the alpha 2B-ligand binding site, and differs from the prejunctional alpha 2-adrenoceptors of rat vas deferens and submandibular gland, which resemble the alpha 2A-ligand binding site.


Effect of alpha 1-adrenoceptor blockade on the development of hypertension in the spontaneously hypertensive rat. There is a large body of evidence to suggest that the sympathetic nervous system plays a critical role in the development of hypertension and vascular medial hypertrophy in the spontaneously hypertensive rat (SHR). The synthesis of a water soluble, specific alpha 1-adrenoceptor antagonist (terazosin) has permitted an examination of the influence of alpha 1-adrenoceptors on those two phenomena. Thus, in the present study, terazosin (43 mg/kg per day) was administered to SHR and Wistar-Kyoto (WKY) rats from 4.5 to 12 weeks of age, and a number of assessments made in vitro and in vivo. In the SHR, the development of hypertension was not prevented by terazosin. The drug did not influence blood pressure in the WKY. This was despite the fact that animals which had been chronically treated with terazosin displayed marked alpha-adrenoceptor blockade in vivo. The response of systolic blood pressure to tyramine and noradrenaline was significantly reduced in animals which had been chronically treated with terazosin. In both the SHR and WKY, chronic administration of terazosin did not influence vascular concentrations of 3-methylhistidine, a biochemical marker for contractile proteins and vascular medial hypertrophy. The results therefore argue against a role of alpha 1-adrenoceptors in the development of hypertension and vascular medial hypertrophy in the SHR.


Rapid fibroblast growth factor-induced increases in protein phosphorylation and ornithine decarboxylase activity: regulation by heparin and comparison to nerve growth factor-induced increases. Fibroblast growth factors (FGFs), like nerve growth factor (NGF), induce morphological differentiation of PC12 cells. This activity of FGF is regulated by glycosaminoglycans. To further understand the mechanisms of FGF and glycosaminoglycan actions in PC12 cells, we studied the regulation of protein phosphorylation and ornithine decarboxylase (ODC) activity by FGF in the presence and absence of heparin. As with NGF, aFGF and bFGF increased the incorporation of radioactive phosphate into the protein tyrosine hydroxylase (TH). The increase in TH phosphorylation was localized to the tryptic peptide, T3. Both T3 and T1 phosphorylations occur in response to NGF, but there was no evidence that aFGF or bFGF stimulated the phosphorylation of the T1 peptide. This result suggests differential regulation of second messenger systems by NGF and FGF in PC12 cells. Heparin, at a concentration that potentiated aFGF-induced neurite outgrowth 100-fold (100 micrograms/ml), did not alter the ability of aFGF to increase S6 phosphorylation or ODC activity. One milligram per milliliter of heparin, a concentration that inhibited bFGF-induced neurite outgrowth, also inhibited bFGF-induced increases in S6 phosphorylation and ODC activity. These observations suggest (i) that acidic and basic FGF activate a protein kinase, possibly protein kinase C, resulting in the phosphorylation of peptide T3 of TH; (ii) that the FGFs and NGF share some but not all second messenger systems; (iii) that heparin potentiates aFGF actions and inhibits bFGF actions in PC12 cells via distinct mechanisms; (iv) that heparin does not potentiate the neurite outgrowth promoting activity of aFGF by enhancing binding to its PC12 cell surface receptor; and (v) that heparin may coordinately regulate several activities of bFGF (induction of protein phosphorylation, ODC and neurite outgrowth) via a common mechanism, most likely by inhibiting the productive binding of bFGF to its PC12 cell surface receptor.


Alveolar macrophage populations are distorted in immunocompromised patients with pneumonitis. Alveolar macrophages (AM) were obtained by bronchoalveolar lavage (BAL) from patients presenting with pneumonitis: 30 human immunodeficiency virus (HIV)-infected individuals and 12 transplant recipients. Nine normal volunteers acted as controls. The cells were washed and cytospins prepared. Monoclonal antibodies (MoAbs) and immunoperoxidase methods were used to analyse the expression of HLA-DR molecules as well as phenotypic macrophage markers. P values apply to the differences between medians using the Mann-Whitney test. Median percentages of macrophages, lymphocytes and neutrophils were similar in all three groups. No differences were found in the median percentages of macrophages expressing the monocyte phenotype (MoAb UCHM1, CD14). However, in HIV-infected patients and transplant recipients a median of only 45% of macrophages expressed the pan-macrophage phenotype identified by MoAb EBM11 (CD68) in contrast with 98% in the normal volunteers. The AM population expressing the dendritic cell marker (MoAb RFD1) was also markedly reduced in both groups of immunocompromised patients (2 vs 28% in normal volunteers). Transplant recipients had significantly more phagocytic cells identified by MoAb RFD7 than the HIV-infected patients (25 vs 2%), but the numbers were still low when compared with the volunteers (48%). HLA-DR expression on BAL cells was reduced by 90% in both immunocompromised groups. For the transplant recipients, severity of pneumonitis was correlated with expression of dendritic cell marker RFD1, (Spearman's rank correlation r = 0.538, p less than 0.05) and pan-macrophage marker EBM11 (r = 0.581, p less than 0.05), while no such correlation was found in HIV-infected patients. These results suggest that a defective macrophage population is probably a serious factor contributing to immunosuppression.


Secretory leucocyte proteinase inhibitor: inhibition of fibronectin degradation by neutrophil elastase. Degradation of surface-bound fibronectin of the upper respiratory tract by human leucocyte elastase (HLE) was shown to favour colonization of these mucosal surfaces by Gram-negative bacteria. We investigated the degradation of fibronectin by purified HLE and by enzymes released from stimulated human polymorphonuclear leucocytes (PMNs), in the presence of recombinant secretory leucocyte proteinase inhibitor (rSLPI) and alpha 1-proteinase inhibitor (alpha 1-PI), the two main inhibitors of HLE within the airways. Our results show that HLE degraded fibronectin at concentrations as low as 0.2 nM. To inhibit the degradation of fibronectin by pure HLE in an experimental system in which the enzyme was premixed with inhibitor, a twofold molar excess of rSLPI and an equimolar concentration of alpha 1-PI were required. On the other hand, a fivefold molar excess of rSLPI was necessary to inhibit degradation of fibronectin by enzymes released from stimulated neutrophils. In order to estimate the role of oxidants generated by stimulated PMNs in the activation of the inhibitory capacity of rSLPI by stimulated PMNs, we preincubated PMNs with antioxidants such as superoxide dismutase, methionine, catalase or Na-azide prior to stimulation of the cells. Under these conditions, a threefold molar excess of rSLPI over released HLE was required to inhibit the degradation of fibronectin, raising the possibility that either exogenous or endogenous antioxidants in the lung could be important in improving the efficacy of this therapeutic antiprotease. We conclude that a molar excess of rSLPI to HLE is always necessary to inhibit fibronectin degradation by HLE, and that addition of antioxidants partly prevents the inactivation of rSLPI by oxidants released from stimulated PMNs.