The relationship of pharmacokinetics to pharmacological activity: morphine, methadone and naloxone. This review illustrates current approaches to the study of the disposition in man of the strong analagesics morphine and methadone and the narcotic antagonist naloxone. Morphine administered orally is rapidly absorbed but equally rapidly metabolised to morphine glucuronide. This contributes to the diminished oral efficacy of morphine. Following intramuscular administration morphine is very rapidly absorbed. After intravenous injection, the serum levels of morphine during the first 10 minutes are higher and more variable in older patients. The half-life of morphine between 20 minutes and 6 hours is 2 to 3 hours and this value does not appear to be influenced by the age of the patient. Similar half-lives for morphine have been reported to normal volunteers and in anaethetised patients who received morphine. Thus, surgical anaesthesia may not markedly influence morphine half-life and disposition. Based on urinary excretion data in man, accelerated morphine metabolism and excretion do not contribute to morphine tolerance. Methadone is now widely used in the treatment of narcotic abuse. The half-life of methadone averages 25 hours. The prolonged retention of methadone in the plasma may be related to its extensive binding to plasma proteins. With chronic dosing, studies in both animals and man indicate an increase in the metabolism of methadone. Unlike morphine, the urinary excretion of methadone increases with acidification of the urine. Women may metabolise methadone to a greater extent than do men. With the exception of pupillary effects, the plasma levels of methadone correlate poorly with its pharmacological activity. There is a marked variation in methadone plasma levels between patients and within the same patient. Naloxone rapidly disappears from the serum in man and the initial distribution phase has a half-life of 4 minutes. The half-life of naloxone in serum following distribution is 64 minutes. Based on animal studies, the rapid onset of the narcotic antagonist action of naloxone can be related to its rapid entry into the brain, whereas its potency stems in part from its high lipid solubility which allows a high brain concentration to be achieved. The short duration of action of naloxone may result from its rapid egress from the brain.


Clinical pharmacokinetics of beta-adrenoreceptor blocking drugs. All beta-adrenoreceptor blocking drugs seem to be fairly rapidly and completely absorbed from the gastro-intestinal tract. The rate of absorption, however, appears to be lower in elderly patients and possibly also in patients with renal failure than in younger patients. The extent of bioavailability varies considerably between different beta-blockers. Some of these drugs(e.g. alprenolol and propranolol) have a low extent of bioavailability due to a high first-pass elimination effect, while pindolol and practolol for example are in influenced very little by this effect. However, as some beta-blockers from active metabolites, the bioavailability calculated as the ratio between the area under the plasma concentration time curve of unchanged drug after oral and intravenous administration does not give an accurate estimation of the fraction of the biologically active dose reaching the systemic circulation. The beta-blockers so far studied are rapidly distributed in the body. The t1/2 of distribution ranges between 5 to 30 minutes. The apparent volume of distribution varies 3- to 4-fold between the compounds but in all cases the apparent volume of distribution exceeds the physiological body space. In patients with impaired liver function an increase of the volume of distrubution of propranolol has been found. The beta-blockers are relatively rapidly eliminated from the body and most of them have an elimination half-life between 2 to 4 hours. For atenolol, practolol and sotalol higher values have been reported. The most lipophilic beta-blockers are almost completely metabolised in the liver, wheras those of lower lipophilicity are mainly excreted via the kidneys. Impraired liver and kidney function have been found to significantly influence the rate of elimination of those beta-blockers eliminated via the insufficient organ of elimination. Numerous investigators have shown that the beta-blocking effect is linearly related to the logarithm of the plasma concentration. In spite of this relationship, it is difficult from mean data to predict the individual plasma concentration which is necessary for a certain degree of beta-blockade. This might be due to variations in the quantitative formation of active metablolites, individual differences in the plasma protein binding and rather flat plasma level-response curves. Also with respect to the therapeutic effect, the plasma levels vary considerably between individuals. This limits the value of determination of plasma concentrations in order to adjust the therapeutic dose. Our recommendation is that these facilities should be utilised in selected patient groups, eg. those who have a poor therapeutic response to a beta-blocker although the dose is high, and those patient with impaired renal or liver function. The duration of beta-blockade is dose-dependent since the pharmacological effect declines with a constant rate (zero-order kinetics) within relatively wide dosage intervals...


Monoamine metabolites in cerebrospinal fluid and serotonin uptake inhibition during treatment with chlorimipramine. The effects of chlorimipramine on the concentrations of the main metabolites of serotonin (5-HT) norepinephrine (NE), and dopamine, i.e. 5-hydroxyindoleacetic acid (5-HIAA), 4-hydroxy-3-methoxyphenyl glycol (HMPG) and homovanillic acid (HVA), respectively, were studied in cerebrospinal fluid from 14 depressed patients, and related to the serotonin- and NE uptake inhibiting activity in vitro of plasma drawn from the patients. Chlorimipramine inhibited the uptake of both transmitter amines in all patients. During treatment, the levels of 5-HIAA and HMPG in cerebrospinal fluid (CSF) were significantly reduced. HVA levels were reduced in 6 patients and increased in 8 patients; there was no mean change. The decrease in 5-HIAA level in CSF was correlated to the uptake inhibition of 5-HT but there was no corresponding relationship between NE uptake and HMPG levels. The changes in HVA levels were also correlated to the uptake of 5-HT despite the absence of a unidirectional change of this metabolite.


Clinical pharmacokinetics of lorazepam. II. Intramuscular injection. A single dose of 4 mg of lorazepam was injected into the deltoid muscles of six healthy male volunteers. Multiple venous blood samples were drawn during 48 hr after the dose and all urine was collected for 24 hr after the dose. Concentrations of lorazepam and its major metabolite, lorazepam glucuronide, were determined by electron-capture gas-liquid chromatography. Lorazepam was rapidly absorbed from the injection site, reaching peak concentrations within 3 hr. Mean pharmacokinetic pamrameters for unchanged lorazepam were: apparent absorption half-life: 21.2 min; elimination half-life: 13.6 hr; volume of distribution: 0.9 L/kg; total clearance: 58.2 ml/min. Lorazepam glucuronide rapidly appeared in plasma, reached peak concentrations within 12 hr of the dose, then was eliminated approximately in parallel with the parent drug. Within 24 hr a mean of 47.6% of the dose was recovered in the urine as lorazepam glucuronide and less than 0.5% was recovered as unchanged lorazepam.


Toxicity of high-dose flurazepam in the elderly. To assess the potential hazards of flurazepam (Dalmane) therapy of insomnia in the elderly, the relation of dosage and patient age to the frequency of flurazepam-attributed adverse reactions was studied in 2,542 hospitalized medical patients. Adverse reactions, predominantly unwanted residual drowsiness, were reported in 78 flurazepam recipients (3.1%). None of the adverse reactions were serious. The frequency of reported toxicity increased with average daily dose, ranging from 1.3% among those receiving less than 15 mg/day to 12.3% at doses of 30 mg/day or more (p less than 0.001). Toxicity increased with age, progressively from 1.9% among those under 60 to 7.1% among those 80 or over (p less than 0.001). Unwanted effects of high-dose flurazepam were observed much more commonly in the elderly. Only 2.0% of those 70 years of age or older experienced adverse reactions at doses under 15 mg/day, as opposed to 39.0% at 30 mg or more per day. Low doses of flurazepam appear to be safe for elderly individuals, but they are susceptible to unwanted central nervous system depression at high doses.


Quantitative immunological determination of brush-border protein in urine. Their role in the progression of inflammatory and toxic renal damage. In urine concentrates form patients with acute and chronic glomerulonephritis and patients under cytostatic treatment, remarkable amounts of membrane-bound alanine-aminopeptidase, alkaline-phosphatase and gamma-glutamyltraspeptidase could be recognized. With an anti-brush-border antisera membrane-bound enzymes could be differentiated from soluble fractions of other origins. Patients with recognizable membrane proteins in urine showed tendencies toward progression of their kidney diseases. Patients under cytostatic treatment with high dose showed a very early output of these enzymes while others under low dose started after a longer treatment with the excretion of membrane-bound enzymes.


Measurement of carbon dioxide in blood.

Measurement of carbon dioxide in blood. The remarkable combination of physical and chemical properties displayed by carbon dioxide has enabled the development of a very wide variety of analytical methods for its measurement in blood or blood plasma. Both for historical and technical reasons, the gasometric method of Van Slyke and Neill is preeminent, but great skill is needed to realize its full precision and accuracy. The microgasometer of Natelson, however, has served the clinical laboratory well as a practicable manual means of microanalysis for total carbon dioxide. So far as automated analysis is concerned, it is highly significant that one of the first applications of Skegg's continuous flow principle was to the titrimetric determination of total carbon dioxide in serum; the AutoAnalyzer technique remains the most widely used of its kind, in spite of inherent difficulties in specimen handling, instrumental standardization, and quality control. At the same time, it has been pointed out that the routine determination of total carbon dioxide in serum does not offer a useful screening procedure for identifying or characterizing patients with acid-base disorders; full assessment of acid-base status, including pCO2 in selected patients is much more rewarding. The credit for bringing pCO2 measurements within the scope of the clinical laboratory, by means of the interpolation technique, is largely due to Astrup and his colleagues. Nevertheless, continual improvements have been made in the design and performance of the Severinghaus type of pCO2 electrode, so that reliable instruments offering direct readout of blood pCO2 are available from several manufacturers. The more elaborate versions of these instruments are rugged and work-simplified, and they offer automated self-calibration and end-point detection for pH and pO2, as well as pCO2. It will be surprising if such instruments do not come into widespread use.


Treatment of asthma with theophylline and beta adrenergic agents. The understanding of the properties of adrenergic receptors and modification of ring and the N-alkyl side chain constituents have resulted in adrenergic agents with a high degree of specificity for the lung and few cardiac and central nervous system stimulating problems. These agents are useful by aerosol and oral routes, alone and in addition to theophylline for asthma. Theophylline, which acts to increase cyclic AMP by inhibition of phosphodiesterase and beta 2 adrenergic agents which increase cyclic AMP by stimulating adenylate cyclase, are the mainstays of asthma therapy. Therapy is usually begun with theophylline. Persistent symptoms with adequate theophylline levels (10-20 mug/ml) indicates the need for a beta 2 adrenergic agent by aerosol or orally as a supplement. Occasional patients will not tolerate theophylline in any preparation and can be treated with beta 2 adrenergic agents with success. The future holds great promise for improved and safer beta 2 adrenergic agents which will offer the physician a more effective means of treating asthma.


An in vitro investigation of barium meals. A technique is described for the in vitro study of the interaction of barium sulphate suspensions, used as radiopaques, with rat ileum. The technique, which allows close approximation to the in vivo situation with accurate control of the experimental conditions, was shown to give reproducible results. The thickness of the radiopaque retained at the gut surface was related to the concentration of the suspension, but was not significantly affected by the pH of the suspension. Less viscous suspensions gave better coating of the gut surface. The nature of the stabilizing agent or the surface charge carried by the particles does not affect the adhesion of the particles to the ileal mucus.


Effect of ultrasonic nebulization on arterial oxygen saturation in chronic obstructive pulmonary disease. Twenty patients with mild to severe chronic obstructive pulmonary disease received ultrasonic nebulization to assess the danger of short-term changes in blood gas levels during this therapy. The status of arterial oxygenation was monitored during 20 minutes of therapy and for 20 minutes following therapy. In nine patients with periodic studies of arterial blood, the mean change in arterial oxygen pressure from base line was a decrease of 0.8 mm Hg at ten minutes into therapy, 2.8 mm Hg at the conclusion of therapy, and 2.9 mm Hg 20 minutes after therapy. In all 20 patients, ear oximetric studies showed only a small mean change at ten minutes into therapy, at the end of therapy, and at 20 minutes after therapy. Changes in the status of arterial oxygenation during and after therapy with ultrasonic nebulization in a group of patients with chronic obstructive pulmonary disease are generally small and of no statistical and limited clinical significance; however, alarming falls in arterial oxygenation can occur and cannot be predicted by base-line testing of pulmonary function or studies of arterial blood. It would be prudent to monitor patients with chronic obstructive pulmonary disease during therapy with ultrasonic nebulization or to withhold therapy altogether.


Controlled comparison of bromazepam, amitriptyline, and placebo in anxiety-depressive neurosis. Seventy-two private practice patients with moderate or severe anxiety-depressive neurosis received mean daily oral doses of 23.8 mg bromazepam, 94 mg amitriptyline, or 4.6 capsules of placebo in a double-blind four-week study. The patient's condition was assessed initially and  at weekly intervals by using the Brief Psychiatric Rating Scale and the Hamilton Psychiatric Rating Scale for Depression. From the first through the fourth week evaluations, a larger proportion of patients improved on bromazepam than on amitriptyline. Bromazepam was also superior to amitriptyline and placebo in the degree of improvement made Statistical significance (p less than 0.05) of the changes noted after one week was even greater after four weeks, particularly in BPRS items of somatic concern, depressive mood, anxiety and tension and in nearly all representative psychic and somatic symptoms on the depression scale, confirmed by global evaluation. Compared to bromazepam patients, amitriptyline patients had significantly severer adverse reactions which were the major cause of the group's higher dropout rate (66% vs 33%). The prompt clinical response to bromazepam contributed to its superior safety and patient progress in that it was possible to carefully titrate dosage and thus help to control adverse reactions and allow patients to maintain alertness and productivity under therapy.


Characteristics of a microsomal cytochrome P-448-mediated reaction. Ethoxyresorufin O-de-ethylation. Certain characteristics of ethoxyresorufin O-de-ethylation, as catalyzed by microsomes of liver, lung, and intestine of control and pretreated rats and hamsters, were studied. The results support previous suggestions that the reaction is catalyzed primarily by a 3-methyl-cholanthrene (MC)-inducible mono-oxygenase which has a 448-nm absorption maximum in the reduced-CO difference spectrum. Ethoxyresorufin exhibited a type I binding spectrum with liver microsomes from MC-induced rats, but there was no clear interaction with microsomes from control or phenobarbital (PB)-induced rats. Maximum MC-induction of type I binding and de-ethylase activity coincided with the appearance of a cytochrome P-450 spectrum whose absorption maximum was shifted to 448 nm. Low concentrations of alpha-naphthoflavone (ANF) or benzo[a]pyrene (BP) inhibited the de-ethylation with liver microsomes of MC-treated rats (150 approximately 10(-9)M) but not those of control rats. A kinetic analysis of BP inhibition of this reaction showed it to be competitive. Inhibition of the MC-induced liver microsomal reaction by low concentrations of BP or ANF diminished rapidly with time. MC-induced rat liver microsomal de-ethylation of ethoxyresorufin was less sensitive than the PB-induced reaction to inhibition by metyrapone or SKF 525-A (I50 approximately 10(-6) - 10(-4)M). However, microsomes from rat liver, lung, and intestine had very low constitutive activities (less than 0.1 nmol/min/mg of protein). MC greatly induced the de-ethylation reaction in liver (200 X), intestine (40 X) and lung (10 X). De-ethylation of ethoxyresorufin in microsomes from control and MC-induced rat lung was inhibited by low concentrations of either ANF or BP (I50 approximately 10(-8) M). Control hamster liver microsomes were several times more active in de-ethylation than control rat liver microsomes, but MC-induction of hamster liver was only 1/10 of that in rat liver. Control hamster lung activity was similar to that of control rat lung, but was not appreciably induced by MC.


Microsomal glucuronidation of a quaternary ammonium compound, 3-hydroxyphenyltrimethylammonium. 3-Hydroxyphenyltrimethylammonium (HPTMA) is glucuronidated in vitro by rat liver microsomes supplemented with UDP-glucuronic acid. Little reaction occurred in the postmicrosomal supernatant fraction. Triton X-100 doubled the maximal velocity for the microsomecatalyzed reaction without altering the apparent KM value for HPTMA. This is the first report of glucuronidation of a quaternary ammonium compound in vitro.


The perinatal development of epoxide-metabolizing enzyme activities in liver and extrahepatic organs of guinea pig and rabbit. We have measured the activities of epoxide hydrase in microsomes and glutathione S-epoxidetransferase and glutathione S-aryltransferase in cytosol fractions of liver, lungs, kidneys, and small intestine from fetal and neonatal guinea pigs and rabbits. The rates at which adult values of these enzyme activities are reached in extrahepatic tissues differ from the rates of maturation of the hepatic enzyme activities for both species. In addition, the two pathways of epoxide metabolism studied here developed with age at different rates in any one organ. However, both cytosol glutathione S-transferases showed very similar developmental profiles in any one organ. It was especially interesting that the activities of both glutathione S-transferases were within the adult range in pulmonary cytosol fraction of guinea pig and rabbit before birth. Intestinal microsomes did not have adult values for epoxide hydrase activity until several weeks after birth. A feature common to both epoxide-metabolizing activities in hepatic and extrahepatic organs was a drop in mean specific activity, sometimes not statistically significant, around the time of birth. This decrease appeared to be due to dilution of the active enzyme with other protein, inasmuch as the total organ activity, in general, showed no such decline. We found that the pattern of development of hepatic microsomal epoxide hydrase activity was similar to developmental patterns published by others for hepatic microsomal mixed-function oxidases, and also that development of hepatic cytosol glutathione S-transferase was similar to hepatic development of glutathione S-transferase towards other substrates described in the literature.


Metabolism of di-2-ethylhexyl phthalate by subcellular fractions from rainbow trout liver. Trout liver homogenates metabolized di-2-ethylhexyl phthalate (DEHP) to monoethylhexyl phthalate (MEHP) without added NADPH and to MEHP and more polar metabolites with added NADPH. Both hydrolysis and oxidative metabolism of DEHP were inhibited by piperonyl butoxide. The 10,000g pellet, 100,000g pellet and 100,000g supernatant fraction from liver homogenates all catalyzed the hydrolysis of DEHP and all but the 100,000g supernatant fraction showed the shift to more polar metabolites with added NADPH; serum also catalyzed the hydrolysis of DEHP. Measurement of the microsomal marker, glucose 6-phosphatase, and the mitochondrial marker, succinic dehydrogenase, revealed that DEHP-hydrolytic activity was associated with microsomes and the 100,000g supernatant fraction, whereas DEHP oxidation was associated only with microsomes.


Biotransformation of D(-)-ephedrine and L(+)-ephedrine in the rabbit, in vivo and in vitro. Investigations were carried out with radiolabeled D(-)-ephedrine and L(+)-ephedrine to establish whether differences exist in their metabolic fate in the rabbit, in vivo and in vitro. In liver microsomal preparations, a) D(-)-ephedrine was metabolized at a faster rate than L(+)-ephedrine, b) benzoic acid was formed from D(-)ephedrine at a rate about three times greater than from the L(+)-isomer, and c) the relative amounts of norephedrine and 1-phenyl-1,2-propranediol formed from both ephedrine isomers were nearly identical throughout the entire incubation period. In vivo, both ephedrine isomers were extensively metabolized and the majority of total radioactivity (71-91%) was excreted within 24 hr. A greater 14C-excretion rate was observed for L(+)-ephedrine. From an analysis of 0- to 24-hr urine, it was found that a) 47-50% of the urinary 14C was attributable to acidic metabolites (hippuric acid and benzoic acid) from L(+)- and D(-)-ephedrine, b) from 4 to 16% of the total 14C obtained with both isomers was accountable as 1-phenyl-1,2-propanediol, either free or as a glucuronide conjugate, c) no appreciable quantities of sulfate or glucuronide conjugates of p-hydroxylated metabolites of ephedrine or norephedrine was detectable, and d) small amounts (less than 4% of metabolites corresponding to unchanged ephedrine, norephedrine, or 1-hydroxy-1-phenyl-2-propanone were found in urine of animals given either isomer. These experiments indicate that the major pathway for the biotransformation of D(-)-ephedrine and L(+)-ephedrine involves N-demethylation and oxidative deamination of the side chain.


Identification of glucuronide metabolites of benzomorphan narcotic analgesic drugs in bile from the isolated perfused rat liver by gas chromatography and mass spectrometry. The metabolism of four benzomorphan compounds was studied in the isolated perfused rat liver, and glucuronide metabolites were identified by combined gas chromatography-mass spectrometry (GC/MS). Cyclazocine, ketocyclazocine, volazocine, and pantazocine were each added to the perfusate of the isolated perfused rat liver and the bile collected for 3 hours. The residue from evaporation of the bile was derivatized with the dimethylsulfoxide anion and methyl iodide, and the permethylated glucuronide metabolites were identified by GC/MS. The four compounds were hydroxylated by the liver and excreted in the bile as phenolic glucuronides. For example, permethylated hydroxycyclazocine glucuronide had a mass spectrum with a molecular ion at m/e 533 and fragment ions at m/e 301 (aglycone), m/e 260 (loss of cyclopropyl group) and prominent ions at m/e 232, 201, 169, 141, and 101 caused by fragmentation of the permethylated glucuronic acid moiety. Perdeuteriomethylation demonstrated that pentazocine, volazocine, and cyclazocine were further metabolized by methylation of one hydroxy substituent and glucuronidation on the other. Pentazocine, cyclazocine, and ketocyclazocine were also metabolized to phenolic glucuronides of the parent drugs. N-deakylated metabolites  of pentazocine, volazocine, and cyclazocine were identified both as permethylated glucuronic acid conjugates and as the trimethylsilyl derivatives of the aglycones, obtained by enzymatic hydrolysis on the conjugates in bile.


Mirex-induced impairment of hepatobiliary function. Suppressed biliary excretion of imipramine and sulfobromophthalein. Effect of pre-exposure to the pesticide mirex on hepatic uptake, metabolism, and biliary excretion of the tricyclic antidepressant, imipramine (IMP), was studied by using isolated perfused rat liver preparations obtained from control and treated animals. Pretreatment of male rats with mirex (50 mg/kg/day, po, for 3 days) resulted in a marked suppression (91%) of biliary excretion of endogenously formed polar metabolites of IMP. This impairment of biliary excretory function is related neither to the bile flow nor to the rate of metabolism of IMP. These conclusions are supported by the following observations: 1) pre-exposure to mirex results in a significant increase in bile secretion; 2) endogenously formed metabolites of IMP accumulate in increasing concentrations in the perfusate of liver preparations from mirex-treated rats; 3) over 98% of the IMP was metabolized by livers of both control and mirex-treated rats. Furthermore, biliary excretion of exogenously provided polar metabolites of IMP was also suppressed by 88% of that of control livers. Addition of mirex (5 X 10(-5) M) to the perfusate of control liver preparations was without effect on biliary excretion of IMP metabolites. Biliary excretion of sulfobromophthalein was also markedly suppressed (90%) by preexposure to mirex. These results suggest that mirex-induced impairment of hepatobiliary function is not specific to substrates. The mechanism of mirex-induced impairment is located at the site of transfer of otherwise readily excretable substances such as metabolites of IMP and sulfobromophthalein.


Metabolic fate of phenobarbital. A quantitative study of p-hydroxyphenobarbital elimination in man. Biotransformation of phenobarbital (PB) to p-hydroxyphenobarbital (PHPB) was studied quantitatively by gas-liquid chromatography in 8 epileptic patients who were receiving an established regimen of antiepileptic drugs including PB. PB and both conjugated and unconjugated PHPB were present in each patient's urine; m-hydroxyphenobarbital (MHPB) was not detected despite an assay sensitivity of 0.25 mug/ml. Incubation of the urine with beta-glucuronidase, but not with arylsulfatase, liberated PHPB which was, therefore, presumed to be conjugated with glucuronic acid. In general, the patients' urine contained more PB than total PHPB. Recovery of the patients' total daily dose of PB ranged from 24 to 77% (mean, 42%). After receiving a single iv dose of PB, PB and both conjugated and unconjugated PHPB were found in a normal volunteer's urine throughout a 16-day collection period; 30% of the dose was recovered. PB excretion was proportional to urine volume in the volunteer and in two additional patients who were made to vary their daily fluid intake. PHPB was not detected in the cerebrospinal fluid of 10 patients receiving PB. Neither PB, PHPB, nor MHPB were detected in the feces of four patients. These results suggest that metabolites other than PHPB or MHPB may be important in the elimination of PB in man.


N-Hydroxylation of pentobarbital in man. After oral administration of 14C-labeled pentobarbital to healthy subjects, most ot the radioactivity was recovered in urine over a period of 6 days. Only a minute amount (approximately 1%) of unchanged pentobarbital was found in the urine. Four major metabolites were found and isolated. One was 3'-hydroxypentobarbital, which has been previously identified by Maynert. The second could be identified as N-hydroxypentobarbital on the basis of its spectral and chemical properties. The other two metabolites were not identified.


Narcotic and narcotic antagonist pKa's and partition coefficients and their significance in clinical practice. The pKa's, partition coefficients and drug distribution coefficients (apparent partition coefficients) have been investigated for a number of narcotics and where possible for their congener narcotic antagonist. These studies were carried out by a novel microelectrometric titration technique as a function of temperature and pH. This method enables one to determine not only the dissociation constants to deconvolute overlapping pKa's, but also to determine the solubilities and oil-water distribution of these various drugs. The drug distribution coefficients displayed marked sensitivity to pH at values which span the range of attainable human physiological pH values. This has significant pharmacological implications for proper choice and scaling of drug dosages under various clinical situations among which are cited hyperventilation under a general anesthetic while concomitantly under a narcotic analgesic, obstetetrical analgesia, and medical and anti-abuse usage of narcotic antagonists. The partition coefficients and drug distribution coefficients were noticeably different at 20degreesC (where such measurements are customarily made) from those at 37degreesC (body temperature). Furthermore, various drugs exhibit very non-equivalent increases in drug distribution coefficients with increasing temperature, ranging from 21% for naltrexone. This non-regularity indicates that it will not be valid to extrapolate by any constant factor the measurements made at lower temperatures. Even the true partition coefficients increase with temperature from 20degrees to 37degreesC.


Metabolism of sudoxicam by the rat, dog, and monkey. Sudoxicam, N-(2-thiazolyl)-4-hydroxy-2-methyl-2H-1,2-benzothiazine-3-carboxamide 1, 1-dioxide, was prepared in radiolabeled form and administered to rats, dogs, and monkeys. Urine contained approximately 60, 25, and 49% of the label given to rats, dogs, and monkeys, respectively; the remainder was cleared via feces. In addition to some unchanged drug, urine from all species examined contained two major metabolites. These were identified from their mass spectra as the thiohydantoic acid and thiourea resulting from scission of the thiazole ring of sudoxicam.


Clinical trial in post-addicts with oxilorphan (levo-BC-2605): a new narcotic antagonist. Oxilorphan (levo-BC-2605) is a new, long-acting, narcotic antagonist that has agonist properties. Twenty-one (21) heroin addicts in Los Angeles were detoxified and given at least one oral dose of oxilorphan. Only three (14.3%) patients took daily doses for 14 days, which was the maximal time allowed for oxilorphan administration in this study. The remainder discontinued oxilorphan because of subjective side effects or for unknown reasons. Side effects most responsible for dropouts were dysphoria, insomnia, weakness, hallucinations, nausea, drowsiness and anorexia. Oxilorphan provided 24-hour protection with a single, oral dose, but subjective side effects encountered during inductiolinical trials with oxilorphan should be attempted with other addict populations to fully determine its potential therapeutic value.


Renal N-oxidation of trimethylamine in the chicken during tubular excretion. The Sperber technique of infusion into the renal portal circulation in chickens was used to investigate in vivo the renal tubular transport and renal metabolism of trimethylamine (TMA). When 14C-TMA was infused at a rate of 1 x 10(-9) mol/min the transport efficiency (TE), that is, the tubular excretion of the 14C-label relative to excretion of simultaneously infused paminohippuric acid, was 0.70. Progressive addition of unlabeled TMA up to infusion rates of 1 x 10(-5) mol/min produced a progressive fall in the TE of the 14C-label. Identification of the 14C-label excreted in the urine revealed that approximately 85% of the infused 14C-TMA was excreted by the infused kidney as a single metabolite over the entire range of infusions. By use of the techniques of low-voltage electrophoresis, high-voltage electrophoretic mobility-pH profile, and gas chromatography/mass spectrometry, the renal metabolite was found to be identical with standard 14C-trimethylamine oxide (TMAO). At a TMA infusion rate of 1.5 x 10(-6) mol/kg/min reaching the infused kidney, the rate at which TMAO was formed and excreted by the kidney was 0.12 x 10(-6) mol per g of kidney per min. When 14C-TMAO was infused into chickens its TE was 0.11, which was not evidence for active excretory transport. Infused TMA was almost entirely metabolized in vivo to its N-oxide, TMAO, which then entered the urine. The renal tubular excretion of 14C during infusion of 14C-TMA was inhibited by the cationic blocker of transport, quinine, and by the anionic blocker of transport, probenecid.


[An unusual case of panarteritis nodosa associated with chronic mercury poisoning (author's transl)]. In a 50-year-old woman, working as a dental assistant for more than ten years, chronic mercury poisoning developed insidiously, apparently from careless handling of mercury-amalgam. The main signs consisted of mental and neurological changes such as erethism, tremor and mercurial psellism. Peripheral arterial circulatory disorders occurred in the course of the disease, as well as abdominal colic and a polyneuropathy, which provided the first clues to panarteritis nodosa subsequently confirmed histologically.


Studies on the N-demethylation and O-de-ethylation of ethylmorphine by hepatic microsomes from male rats. On the basis of inhibition studies of the dealkylation of morphine and norcodeine, George and Tephly concluded that O-dealkylation and N-dealkylation are catalyzed by different enzymes. We have examined the microsomal dealkylation of 3-O-[1'-14Clethylmorphine by measuring HCHO colorimetrically and [1-14C]acetaldehyde radiometrically. We find that the KM for the O-de-ethylation is 57 muM, which is quite close to the KS(71 muM) for the type I binding of ethylmorphine in similar preparations. On the other hand, the KM for N-demethylation was 250 muM. Further, the N-demethylation was stoichiometric with the stimulation of both NADPH-cytochrome P-450 reductase and NADPH oxidase, whereas the sum of the N-demethylation and O-de-ethylation was significantly greater, suggesting that the O-de-ethylase activity does not involve stimulation of either of these two activities. Induction with phenobarbital increaesed N-demethylation 118% but did not affect O-de-ethylation. Finally, D2O inhibited the N-demethylase more than the O-de-ethylase.


Perfused lung preparation for studying altered gaseous environments. An isolated perfused lung (IPL) preparation was used to investigate the influence of acute environmental stress on lung substrate metabolism. The IPL apparatus consists of four perfusion flasks housed in a temperature-controlled Lucite box with a circulation fan. Lungs are ventilated by a positive pressure ventilation pump. The ventilation is arranged so that the lung can be ventilated with any desired gas composition with concomitant collection of expired gases. The perfusion medium is circulated at 10 ml/min with a peristaltic blood pump, and passes through a specially designed chamber to dampen pulmonary pressure and remove emboli. The perfusion medium presently used in our experiments consisted of washed bovine red blood cells resuspended to a 15% hematocrit with Krebs-Henseleit bicarbonate buffer containing 6% dialyzed Pentex bovine serum albumin. Circulating substrates include 6muM glucose and 0.4muM palmitate. The pH is adjusted to 7.4 with 0.8M Na carbonate. Lungs perfused for 1.5 hr with this apparatus maintain viability, show little edema, maintain blood gases, and show linear incorporation of labeled glucose into lung lipids. Perfused lungs made hypocapnic show a significant (p less than 0.05) rise in lactate and pyruvate, while perfused lungs made hypercapnia show a significant decrease in pyruvate with no change in lactate.


Increase in activity of partially purified alkaline phosphatase after treatment with Mg2+, Zn2+ and lysolecithin. When lysolecithin predispersed in 0.15 mol/l KCl was sonicated with partially purified alkaline phosphatase, the enzyme activity was increased. Lysolecithin moderately modified the kinetic parameters by increasing the apparent Vmax and decreasing the apparent Km. The pH profile of the enzyme was shifted slightly from a peak at pH 9.5 for the soluble enzyme to a plateau between pH 9.5 and 10.2 for the lysolecithin enzyme mixture. In addition, lysolecithin enhanced the thermostability and resistance of the soluble enzyme preparation to chemical denaturants.


Changes in the activities of the enzymes of hepatic ketogenesis in the rat between late fetal life and weaning. The activities of hydroxymethylglutaryl-CoA synthase and hydroxymethylglutaryl-CoA lyase have been determined in the mitochondria and cytosol of the liver during development of the rat. Both mitochondrial enzymes exhibit similar developmental patterns with rapid rises in activity after birth, peaks of activity during early and late suckling and a trough during the mid-suckling period and a slight fall in activity (to the adult values) after weaning. Both cytosolic enzymes have low activities at all ages studied and exhibit no major developmental changes.


Regulation of nitrogen catabolic enzymes in chick liver: effects of insulin. Previous studies have shown that a group of nitrogen catabolic enzymes including xanthine dehydrogenase, purine nucleoside phosphorylase, and tyrosine aminotransferase are all increased in chick liver by dietary protein as well as single amino acids (e.g. methionine) and certain antimetabolites (e.g. hydrazine). A similar enzyme response pattern can be obtained with insulin. This hormone causes an enhanced rate of XDH synthesis and gives nonadditive results with protein, hydrazine and methionine. Furthermore, a vitamin B6 dependency was observed in responses to both high protein diets and insulin, all suggesting a common regulatory mechanism. In this system dietary protein and insulin may act similarly by increasing the availability of amino acids to the liver -- in one case by supplying amino acids through the diet and in the other by increasing amino acid uptake.


Recent advances in equine reproduction.

Recent advances in equine reproduction. Mares rarely ovulate in winter; ovulation is induced by increase in daylight length. Ova accumulate in the oviducts of unserved mares. During pregnancy, corpora lutea accumulate; all regress together at mid pregnancy. Plasma progesterone levels rise and oestrogen levels fall towards the end of pregnancy. Methods are available for early termination of pregnancy and for induction of parturition. Pregnancy can be diagnosed efficiently by rectal examination, and by immunological assay of pregnant mare serum gonadotrophin. Service at the foal heat is associated with an increased prevalence of early embryonic death; twinning is the commonest single cause of abortion. Spontaneous prolonged dioestrus is common in summer but may be effectively treated. Bacterial endometritis may result mainly from secondary pathogenic activity by organisms of the normal uterine flora; diagnosis by endometrial smear examination is accurate and methods of treatment have improved. The virus of horse pox has been identified, and the occurrence of equine infection with Mycoplasma has been confirmed. In the male, recent work has emphasized that reproductive function is seasonal. The presence or absence of an undescended testis can now be accurately determined.


Heart rate and ventilation in relation to venous [K+], osmolality, pH, PCO2, PO2, [orthophosphate], and [lactate] at transition from rest to exercise in athletes and non-athletes. To evaluate to what metabolci event in contracting muscles heart rate (HR) and VE are related, time courses of femoral and cubital venous [K=], osomolality (OSM), pH, POC2, PO2, [lactate], and [orthophosphate] ([Pi]) at onset of exercise were studied in athletes (TR) and non-athletes (UT) and compared to time courses of HR and VE. During ischaemic work with the calf muscles it could be shown that most of these blood constituents were only released from contracting muscles. Thus their time courses reflected the metabolic events in working muscles being not essentially disturbed by non-working parts of the body. Ischaemic work induced, however, substantial increases of HR and VE. In the course of non-ischaemic bicycle work HR and VE rose more rapidly in TR than in UT but were lower in TR during the steady state. During non-ischaemic work only the increased of femoral venous [K=1 closely mimicked the cardiorespiratory transients in TR as well as in UT. None of the other femoral venous substances showed such a rapid change or such typical variations between TR and UT. Cubital venous [K=1 and [Pi] approached femoral  venous concentrations only in second minute after start whereas pH, PCO2, and OSM increased mainly in venous outflow from contracting muscles. PO2 decreased in femoral venous blood of TR and UT, but in cubital venous blood it remained depressed only in UT. It was discussed that the cardiorespiratory adjustment during the initial stages of work was related to K+ release in working muscles and not to O2 consuming or H+ producing processes, nor to release of Pi or increase of OSM.


Photooxidation of human serum albumin and its complex with bilirubin. Irradiation with visible light of human serum albumin in aqueous solution at pH 8, in the presence of catalytic amounts of rose bengal or methylene blue, resulted in random oxidation of the histidine residues in the protein under consumption of one mole O2, and release of somewhat less than one proton, per histidine residue degraded. An increase of light absorption at 250 nm was proportional to the amount of oxygen consumed. Bilirubin bound to the oxidized protein showed an increased light absorption at its maximum, 460 nm, and a decreased binding affinity, indicating a conformational change of the protein on oxidation of histidine residues. This change also resulted in a slight perturbation of tyrosine light absorption, corresponding to a shift of the chromophore to more polar surroundings. Further, a sensitized oligomerization of albumin was observed, independent of oxidation of the histidine residues, and not consuming oxygen. Irradiation of a complex of human serum albumin with one molecule of bound bilirubin, in the absence of a sensitizing dye, resulted in a fast, non-oxygen consuming process whereby the light absorption maximum of the pigment was shifted 4 nm towards longer wavelength and part of the bilirubin was converted to a more polar pigment, bound less firmly to the protein. This was followed by a relatively slow oxidation of the pigment under uptake of one mole O2. Parallel photooxidation of the protein carrier could not be detected. It is considered possible that the fast, anaerobic process is operative in phototherapy of hyperbilirubinemia in the newborn. Serum albumin is probably not oxidized during this treatment.


CO2-mediated control of fatty acid metabolism in isolated hamster brown-fat cells during norepinephrine stimulation. 1. Addition of norepinephrine to isolated hamster brown-fat cells suspended in Krebs-Ringer phosphate buffer induces a pronounced, but temporary increase in respiratory rate. 2. If Krebs-Ringer phosphate buffer is bubbled with CO2 prior to the addition of cells and norepinephrine, the respiratory capacity of the cells is further potentiated and most important, the respiration is maintained at a high rate until the medium becomes depleted of oxygen. 3. This respiratory pattern cannot be obtained in CO2-bubbled Krebs-Ringer bicarbonate buffer. 4. The results indicate that CO2 has a regulatory effect on fatty acid metabolism in isolated hamster brown-fat cells.


Synthesis of stereospecifically deuterated phenylalamines and determination of their configuration. 1. Starting from trans-cinnamic acid a chiral (-)3-phenyl-[2,3-2H]propionic acid has been synthesized using Clostridium kiuyveri cells as catalyst. 2. The chiral dideuterated acid has been converted by chemical methods to a mixture of (2R) and (2S)-phenyl[2,3-2H]-alanine. 3. By means of 1H nuclear magnetic resonance spectroscopy and the action of D and L-amino acid oxidase the configuration of the phenylalamine has been shown to be (2R, 3S) and (2S, 3S), respectively. The labelled phenylalanine is thus sterically and isotopically homogenous at position 3 but heterogenous at position 2.


Stereospecificity of phenylpyruvate tautomerase. A convenient method for the preparation of chirally labelled phenylpyruvates. 1. By 1H nuclear magnetic resonance spectroscopy it has been shown that phenylpyruvate tautomerase from beef kidney catalyses the stereospecific exchange of one of the enantiotopic 3H-atoms in the side-chain of the substrate with solvent protons, the rate of spontaneous exchange being slow under physiological conditions. 2. Using monodeuterated phenylpyruvate of known absolute configuration it has been shown that the tautomerase removes specifically the 3-pro-R hydrogen atom of the substrate. 3. The circular dichroism spectra of the two enantiomeric 3-phenyl-[3-2H]pyruvates have been determined. 4. Some implications of these findings for the investigation of the metabolism of aromatic amino acids are discussed.


Mitochondrial and cytosolic NADPH systems and isocitrate dehydrogenase indicator metabolites during ureogensis from ammonia in isolated rat hepatocytes. 1. Citrate isocitrate and 2-oxoglutarate levels were determined in isolated rat hepatocytes and in particulate and soluble fractions, thereof, obtained by the digitonin and silicone oil fractionation technique. 2. Caculated from isocitrate/2-oxoglutarate ratios ("indicator metabolite method"), the redox potential of mitochondrial free NADPH is -402 mV, whereas that of the extramitochondrial (cytosolic) space is about 10 mV more positive, -392 mV. 3; Addition of ammonia (either as ammonium chloride or from urea plus urease) to isolated hepatocytes causes preferential oxidation of mitochondrial NADPH, is demonstrated by spectrophotometry of the dihydro band and by the changes in the isocitrate/2-oxoglutarate ratios. The redox potential difference of free NADPH between mitochondria and cytosol is abolished or even reserved. 4. It is concluded that during urogenesis from ammonia mitochondrial isocitrate oxidation is shifted largely in favor of the NADP-linked as opposed to the NAD-linked enzyme; isocitrate concentration under these conditions is less than 10 muM, below the Km (isocitrate) of the NAD-linked enzyme but in the range of that for the NADP-linked enzyme. 5. Both in the absence and in the presence of ammonia there is a concentration gradient across the mitochondrial inner membrane (from mitochondria to cytosol) for citrate, isocitrate, and also, to a smaller extent, for 2-oxoglutarate. 6. These results and data in the literature on enzyme activity are in agreement with the assumption of near-equilibrium of NADP-dependent isocitrate dehydrogenases in the mitochondrial matrix and cytosolic spaces in the absence of ammonia; accordingly, during urea formation from added ammonia the redox potential of mitochondrial free NADPH is increased to -391 mV or possibly even higher if there exists an indicator error under this condition.


Preparation of coenzymic activity of soluble polyethyleneimine-bound NADP+ derivatives. Alkylation at N-1 of the NADP+ adenine ring with 3,4-epoxybutanoic acid gave 1-(2-hydroxy-3-carboxypropyl)-NADP+. Enzymic reduction of the latter, followed by alkaline Dimroth rearrangement and enzymic reoxidation, gave N6-(2-hydroxy-3-carboxypropyl)-NADP+. On the other hand, bromination at C-8 of the NADP+ adenine ring, followed by reaction with the disodium salt of 3-mercaptroproionic acid, gave 8-(2-carboxyethylthio)-NADP+. Carbodimide coupling of the three carboxylic NADP+ derivatives to polyethyleneimine afforded the corresponding macromolecular NADP+ analogues. The carboxylic and the polyethyleneimine derivatives synthesized have been shown to be co-enzymically active with yeast glucose-6-phosphate dehydrogenase, liver glutamate dehydrogenase and yeast aldehyde dehydrogenase. The degree of efficiency relative to NADP+ with the three enzymes ranged from 17% to 100% for the carboxylic derivatives and from 1% to 36% for the polyethyleneimine analogues. On comparing the efficiences with the three enzymes of the N-1 derivatives to the one of the corresponding N6 anc C-8 analogues, the order of activity was N-1 greater than N6 greater C-8, except in the case of the carboxylic compounds with glutamate dehydrogenase, where this order was inverted. None of these modified cofactors were active with pig heart isocitrate dehydrogenase.


Purification and properties of blood-group-specific lectins from Vicia cracca. The lectins from the seeds of Vicia cracca react specifically with human blood group A erythrocytes. They were purified by affinity chromatography on an adsorbent containing matrix-bound N-acyl-D-galactosamine. By a continuous pH gradient the lectins could be separated into two fractions each of which was shown to consist of several agglutinating species. The behaviour of both fractions in affinity chromatography was paralleled by the pH dependence of the interaction with the hapten sugar N-acetyl-D-galactosamine. Both lectin fractions have the same molecular (125000) and subunit (33000) weights, display the same pH dependence of their titre against A1 erythrocytes, and bind to N-acetyl-D-galactosamine at pH 8 with the same constant of about 6 X 10(3)M-1.


Biophysical and enzymological studies upon the interaction of trans-cinnamic acid with higher plant microsomal cytochromes P-450. The interaction of trans-cinnamic acid with the cytochrome P-450 of microsomes derived from washed potato slices has been studied. The washing process increased the specific content of microsomal electron transport components and hence provided a useful material in which to study the interaction. Evidence is presented that the trans-cinnamic acid interacts with the cytochrome P-450, and that this interaction is analogous to "type 1" interactions of other cytochrome P-450 systems. This evidence includes the formation of a "type 1" substrate binding spectrum, an increased rate of reduction of cytochrome P-450 by NADPH in the presence of trans-cinnamic acid, an increased oxygen uptake and NADPH oxidation when trans-cinnamic acid is added to the microsomes in the presence of NADPH, and a close correlation between biophysical parameters of electron transport in the cytochrome P-450 system and enzymological parameters of the trans-cinnamic acid 4-hydroxulation reaction. The investigation has been extended to cytochrome P-450 systems of other tissues and it has been found that the trans-cinnamic acid 4-hydroxylation reaction cannot account for the presence of most of th cytochrome P-450 in several tissues. This suggests that other functions of higher plant cytochrome P-450 chains exist, and that the substrate specificityof the hemoprotein may vary in different plant tissues.


Detergent-resistant phospholipase A of Escherichia coli K-12. Purification and properties. Detergent-resistant phospholipase A, which is tightly bound to the outer membranes of Escherichia coli K-12 cells, was purified approximately 2000-fold to near homogeneity by solubilization with sodium dodecylsulfate and butan-1-ol, acid precipitation, acetone fractionation and column chromatographies on Sephadex G-100 in the presence of sodium dodecylsulfate and on DEAE-cellulose in the presence of Triton X-100. The final preparation showed a single band in the sodium dodecylsulfate gel system. The enzyme hydrolyzes both the 1-acyl and 2-acyl chains of phosphatidylethanolamine or phosphatidylcholine. It also attacks 1-acyl and 2-acylglycerylphosphorylethanolamine. Thus, this enzyme shows not only phospholipase A1 and lysophospholipase L1 activities but also phospholipase A2 and lysophospholipase L2 activities. The enzyme lost its activity completely on incubation at 80 degrees C for 5 min at either pH 6.4 or pH 8.0. It was stable in 0.5% sodium dodecylsulfate at below 40 degrees C. The enzyme was inactivated on incubation for 5 min at 90 degrees C in 1% sodium dodecylsulfate/1% 2-mercaptoethanol/4 M urea. The native and inactivated enzymes showed different protein bands with RF values corresponding to Mr 21 000 and Mr 28 000 respectively, in a sodium dodecylsulfate gel system. Triton X-100 seemed to protect the enzyme from inactivation. The purified enzyme was fully active on phosphatidylethanolamine in the presence of 0.0002% or 0.05% Triton X-100. The enzyme requires Ca2+. From its properties this enzyme seems to be identical with the enzyme purified from crude extracts of Escherichia coli B by Scandella and Kornberg. However, it differs from the latter in its positional specificity and susceptibility to sodium dodecylsulfate. Possible explanation of the difference of positional specificity of the two preparations is also described.


Relation between the gradient of the ATP/ADP ratio and the membrane potential across the mitochondrial membrane. The relation between the intramitochondrial and extramitochondrial ratio ATP/ADP, the transmembrane potential and pH gradient is investigated in the present communication. For this purpose mitochondria are equilibrated with added [14C]ATP in the presence of substrate and oligomycin for eliminating phosphate transfer by ATPase. The membrane potential was measured by the distribution of 86Rb+ in the presence of valinomycin, the  deltapH by the distribution of [14C]acetate. In the energized state by varying deltapsi between 60 and 160 mV, the internal (ATP/ADP)i is decreased 30-fold, the external (ATP/ADP)e remains largely constant. As a result, the deltalog (ATP/ADP)e/(ATP/ADP)i = deltalogphi is increased linerly with deltapsi according to the following relation: deltalogphi = 0.85 deltapsi - 0.35. The deltapH was changed between 0.1 and 0.8 by increasing the Pi concentration causing only a minor decrease of deltalogphi would be expected if the ATP-ADP exchange has a significant electroneutral portion. Also in the uncoupled and respiration-inhibited state the same function between deltalogphi and deltapsi is found as in the energized states. It is concluded that under these conditions the ATP-ADP exchange is largely electrical.


Stabilization of human beta-D-N-acetylhexosaminidase A towards proteolytic inactivation by coupling it to poly(N-vinylpyrrolidone). Human hexosaminidase A was covalently bound to soluble poly(N-vinylpyrrolidone), and the effect of this binding on the enzyme inactivation by various procedures was investigated. Whereas the polymer-bound hexosaminidase underwent inactivation to the same extent as the free enzyme, when exposed to heat or acidic pH, the conjugation to polymer appeared to protect the enzyme towards proteolysis. Thus, the polymer-bound enzyme exhibited considerably higher resistance to treatment of both pronase and macrophage cathepsins. The clearance rate from rabbit blood, of the polymer-bound enzyme (expressed as enzyme activity), was shown to be significantly slower than that of the free enzyme.


The effect of Mg2+ on the Ca2+-binding properties of non-activated phosphorylase kinase. The calcium binding properties of non-activated phosphorylase kinase at pH 6.8 have been studied by the gel filtration technique at calcium concentrations from 50 nM to 50 muM. Taking into account the subunit structure alpha4beta4gamma4 the enzyme binds 12 mol Ca2+ per mol with an association constant of 6.0 X 10(7) M-1, 4 mol with an association constant of 1.7 X 10(6) M-1 and 36 mol with a binding constant of 3.9 X 10(4) M-1 at low ionic strength. In buffer of high ionic strength, i.e. 180 mM NH4Cl or 60 mM (NH4)2SO4, only a single set of eight binding sites with a binding constant of 5.5 X 10(7) M-1 is left. In a buffer containing 155 mM NH4Cl and 10 mM MgCl2, the calcium affinity of these sites is reduced to a KCa of 3.0 X 10(6) M-1, indicating competition between Ca2+ and Mg2+. From these measurements, the binding constant of Mg2+ for these sites is calculated to be 1.7 X 10(3) M-1 is left. In a buffer containing 155 mM NH4Cl and 10 mM MgCl2, the calcium affinity of these sites is reduced to a KCa of 3.0 X 10(6) M-1, indicating competition between Ca2+ and Mg2+. from these measurements, the binding constant of Mg2+ for these sites is calculated to be 1.7 X 10(3) M-1. Additionally, 10 mM Mg2+ induces a set of four new Ca2+ binding sites which show positive cooperativity. Their half-saturation constant under the conditions described is 3.5 X 10(5) M-1, and they, too, exhibit competition between Ca2+ and Mg2+. Since this set of sites is induced by Mg2+ a third group of binding sites for the latter metal must be postulated.


Interactions of corticosterone, 5alpha-dihydrocorticosterone and dexamethasone with proteins in rat-liver cytosol. The intracellular binding of [3H]corticosterone and [3H]dexamethasone and their metabolites to macromolecules in rat liver cytosol was studied in vivo and in vitro. The macromolecules binding corticosterone and its metabolites were characterized as (a) a steroid conjugate-binding (Stokes radius 2.5 nm and sedimentation coefficient 4.1 S in high ionic strength; pI 8.7, (b) transcortin and (c) a glucocorticoid "receptor". Competition experiments indicate that corticosterone and dexamethasone bind to the same site of the glucocorticoid receptor molecule. Different Stokes radii between the corticosterone-receptor and the dexamethasone-receptor complexes (6.9 and 6.3 nm, respectively, in high ionic strength) indicate that the two ligands induce different conformations of the receptor protein. This may be of importance when explaining the qualitative differences between the cellular effects of natural and synthetic glucocorticoids. 5alpha-Dihydrocorticosterone, on the other hand, competed to a very limited extent with dexamethasone for binding sites on the receptor. An assay of the inductive effect on liver tyrosine aminotransferase and tryptophan oxygenase indicated that 5alpha-dihydrocorticosterone was practically devoid of glucocorticoid activity. It is concluded that 5alpha-dihydrocorticosterone probably does not act as the mediator of corticosterone action in rat liver.


Studies by small-angle x-ray scattering of the quaternary structure of dissociation products of the beta-haemocyanin of Helix pomatia. Helix pomatia beta-haemocyanin was split into dissociation products by varying the pH and the ionic strength. The purity of the solution was checked in an ultracentrifuge. Two defined dissociation products were studied in solution by small-angle X-ray scattering. In Tris-HC1 buffer, pH 8.0 and ionic strength 1 M, the following parameters of the dissociation product (tenths) could be determined: molecular weight = 7 x 10(5), volume = 1350 nm3, radius of gyration = 9.0 nm, maximal distance = 28.3 nm, radius of the spherical subunits about 2.6 nm, number of the subunits approximately 19. Tris-HC1 buffer, pH 8.7 and ionic strength 0.01 M, yielded dissociation products (twentieths) with the following parameters: molecular weight = 3.5 x 10(5), volume = 635 nm3, radius of gyration = 7.5 nm, maximal distance = 21.9 nm, radius of the spherical subunits about 2.5 nm. With this information, the assumption that the larger fragment was double the smaller one and the latest biochemical and morphological results, theoretical scattering curves of models were calculated and compared with the experimental curves. Two models are suggested which argee well with the dissociation products in radius of gyration and scattering.


Study of the role of puring phosphoribosyltransferases in the uptake of adenine and guanine by Schizosaccharomyces pombe cells. 1. In the yeast Schizosaccharomyces pombe 972h-, the uptake rate of both adenine and guanine is related to variations in the specific activity of the corresponding phosphoribosyltransferases during the growth of the culture. Furthermore, the mutant strains dap 1, devoid of adenine phosphoribosyltransferase activity, and pur 1, devoid of guanine phosphoribosyltransferase activity have a lowered uptake rate of adenine and guanine respectively, along with an increased apparent Km value for these purines in comparison to the wild-type 972h. 2. The uptake rate of the purines is strongly dependent on the pH of the uptake medium in 972h- as well as in the strains dap 1 and pur 1, the optimum being between pH4 and pH5. 3. A new method of extraction of 5-phosphoribosyl-1-pyrophosphate from the yeast has been devised. Important fluctuations of the P-Rib-P2 pool were measured in S. pombe at different stages of growth, the maximum taking place at the start of the exponential phase, whereas no variations in the specific activity of the P-Rib-P2 synthetase could be observed during the growth. The P-Rib-P2 intracellular content in the mutants devoid of purine phosphoribosyltransferases, namely pur 1, dap 1 and pur 1, dap 1, was increased up to 5-fold as compared to the wild-type strain. 4. The effect of intracellular concentrations of P-Rib-P2, a substrate for phosphoribosyltransferases, on the uptake rate of purines has been studied: addition of formycin to the growth medium lowered simultaneously the P-Rib-P2 intracellular content and the uptake of adenine and guanine. 5. Although our results demonstrate the activating effect of phosphoribosyltransferase activities on the uptake of adenine and guanine, they do not support the hypothesis of a 'group translocation' mechanism.


Modification of the adrenal stress response by age and prior experience. The adrenal stress response was examined in young and mature rats of both sexes by measuring the increase in adrenal tyrosine hydroxylase activity and serum corticosterone following exposure to electric footshock. Exposure to electric footshock for six minutes on three consecutive days elevated tyrosine hydroxylase activity in young and mature female rats and in young male rats, but failed to elevate enzyme activity in mature male animals. This decreased responsiveness of tyrosine hydroxylase in mature male rats could be overcome by giving prior experience with electric footshock. Age, sex, and prior experience interacted a affecting the levels of serum corticosterone in response to a three minute exposure to electric footshock. However, the most dramatic effect was due to prior experience, which reduced themagnitude and altered the time of the peak serum corticosterone response. These data demonstrated that the pituitary-adrenal system can be modified in old animals in a manner similar to the modification seen following infant stimulation, and indicate that several mechanisms may be invilved in the maturation and aging of a species.


Relationship between plasma concentrations and pharmacological effects of labetalol. In healthy normal subjects following the administration of labetalol the pharmacological effects were measured and compared with the plasma concentrations achieved. The inhibition of exercise induced tachycardia and inhibition of exercise induced increases in systolic pressure were significantly related to the administered dose of labetalol. Labetalol was rapidly absorbed from the gastrointestinal tract and peak plasma concentrations occurred two hours after oral administration. There was a linear correlation (r = 0.84) between the logarithm of the plasma concentration and the maximum inhibition of exercise tachycardia at two hours. After intravenous administration there was an immediate reduction in systolic and diastolic blood pressure with a concomitant small increase in heart rate. There was a rapid decline in the associated plasma concentration but the pharmacological effects were maintained in excess of two hours. Our findings are consistent with those of others who have studied the relationship between pharmacological events and plasma concentrations after single doses of other adrenoceptor blocking drugs.


Beta-adrenoceptor blocking and electrophysiological effects of bufetolol in the guinea pig atria. The potency of blockade of bufetolol, a beta-adrenoceptor blocking drug, and effects of bufetolol on the action potential, contractile force and various electrophysiological properties of the atrium were investigated in comparison with propranolol and quinidine. Bufetolol had a pA2 of 8.65 against the positive chronotropic action of isoproternol on the guinea pig sinus node. Bufetolol, 10(-7) g/ml, did not affect the action potential of the atrial muscle, while the drug, 3 X 10(-5) g/ml, significantly decreased the overshoot potential, the amplitude and the maximum rate of rise of the action potential and prolonged the times for 50% and 90% repolarization. The contractile force was reduced by bufetol, 3 X 10(-5) g/ml. The maximum responsive frequency to the driving stimulus was decreased by bufetol, 3 X 10(-5) g/ml.  The excitability of the muscle membrane was suppressed by bufetolo, 3 X 10(-5) g/ml, as indicated by changes in membrane responsiveness, membrane reactivation and strength-duration curve. Propranolol, 10(-5) g/ml and quinidine, 10(-5) g/ml showed similar effects on excitability. The authors suggest that these effects of bufetolol are responsible for its antidyshythmic effects.


Aminotetralins as selective beta-adrenergic agonists. Aminotetralin derivatives M-8 and JOD-176, were studied in relation to isoproterenol for beta-adrenergic activity. M-8 and JOD-176 were found to be very weak in activating cardiac beta-receptors. These compounds were also found to be considerably more active in uterine and bronchial smooth muscle. Because these compounds were also shown to be very inactive in vascular smooth muscle, the possibility that beta-receptors in different smooth muscle types may also differ was suggested.


"Direct" effect of reserpine on various preparations. The action of reserpine added to the bathing solution has been studied in isolated organs, examining various kinds of receptor systems and biological preparations. The investigation has been comparatively carried out in normal and reserpine-pretreated animals. The most important effect of reserpine is the inhibition of the maximum response to noradrenalin in the rat vas deferens, and the inhibition of response to furtrethonium and histamine in the intestine of rat and guinea-pig, respectively. This affect appears to be independent of the release of catecholamines, and is therefore direct, aspecific and similar to the non-competitive effect of papaverine.


[The histaminergic mechanisms in the regulation of prolactin secretion in urethan-anesthetized rats (author's transl)]. In an attempt to detect the existence of histaminergic mechanisms in the regulation of prolactin secretion in rats, the effects of histidine and histamine-receptor antagonists (chlorpheniramine and metiamide) on plasma prolactin levels in urethan-anesthetized rats were investigated in relation to other aminergic mechanisms. Chlorpheniramine was used as an H1-receptor antagonist and metiamide as an H2-receptor antagonist. Wistar male rats were used under urethan anesthesia and blood was obtained by cardiac puncture. Rat plasma prolactin was measured by radioimmunoassay. As already reported, L-DOPA and diethyldithiocarbamate markedly decreased plasma prolactin levels in rats. Dihydroxyphenylserine increased prolactin levels. Brocresine phosphate, a histidine decarboxylase inhibitor, markedly stimulated prolactin secretion in urethan-anesthetized rats. This stimulation was not blocked by pretreatment with histidine or L-DOPA. Histidine alone did not affect plasma levels of prolactin or methyldopamine-induced increase in plasma prolactin levels. On the other hand, histidine significantly stimulated prolactin secretion in chlorpheniramine-treated rats. In contrast, histidine depressed plasma prolactin levels in metiamide-treated rats. These findings indicate that a dopaminergic component is inhibitory and a noradrenergic one is stimulatory in prolactin secretion in rats and further that there exist the histaminergic mechanisms, relatively independent from other aminergic mechanisms, which might also play an important role in the regulation of prolactin secretion in rats. Furthermore, it is suggested that H1-receptor is stimulatory and H2-receptor is inhibitory in prolactin secretion in rats.


Chromosomal breakage in systemic sclerosis and related disorders. Chromosome aberrations such as gaps and breaks of one or both chromatids, acentric fragments, dicentrics, ring chromosomes and other abnormal chromosomes are observed in lymphocyte and fibroblast cultures as well as in direct bone marrow preparations from patients with systemic sclerosis. A serum factor producing chromosome breaks in mitoses from healthy donors was observed in 37 of 42 scleroderma patients. The biochemical nature of this breakage factor is still undefined. Increased breakage is also noted in a high percentage of healthy family members of scleroderma patients. It is also a common feature of related disorders such as lupus erythematosus, dermatomyositis, periarteritis nodosa and rheumatoid arthritis. An increase in chromosome breaks and rearrangements is also present in NZB mice developing spontaneously an autoimmune disorder that has been extensively studied by workers interested in lupus erythematosus. The similarity of the cytogenetic findings provides the opportunity to use these mice as an experimental model to investigate relationships between immunological perturbations and chromosomal aberrations.


Pilot open-label study of alprazolam (U-31,889) in anxious alcoholic out-patients. Twenty out-patients suffering from anxiety and tension after withdrawal from alcohol were treated for 28 days with alprazolam. Three patients dropped out for intercurrent events, and 2 dropped out for recurrent drinking. Of the 15 patients completing the study, analysis of variance showed significant improvement in all Physician's Ratings as well as all patient self-ratings. At the 28th day, 93% of the patients rated moderate to marked improvement on the Physician's Global Impression and Therapeutic Effect, and 93% self rated at least a little better. Side-effects were generally mild and inconsequential. No adverse effects attributable to alprazolam were noted on laboratory evaluations, EKG's or ophthalmologic examinations.


Diphenylpyraline (Lergobine) in the treatment of patients suffering from allergic and vasomotor rhinitis. In a double-blind study, diphenylpyraline (Lergobine) was given to 63 patients whose main symptoms were stuffiness of the nose, increased secretion of mucus, snuffling, sneezing and redness of the eyes. Fifty-seven patients were given placebo for identical symptoms. Diphenylpyraline was found to have a better effect on all the symptoms than placebo. The difference was statistically significant in respect of the discharge of mucus and redness of the eyes, and when the total symptoms were considered as a whole. In atopic patients the better effect of diphenylpyraline was highly significant.


A follow-up study of the use of benoral tablets in non-articular rheumatism. A multicentric follow-up study was conducted in general practice to assess disease characteristics which determine analgesic needs in non-articular rheumatism. Of 127 patients studied, those with chronic conditions such as brachial fibrositis and tennis elbow with a history extending over more than a month tended to require a longer course of treatment than those whose symptoms related to muscles of the trunk and spine. For most patients a one or two week course of Benoral tablets proved adequate in length and efficacy.


Comparison of the in vitro conversion of estradiol-17 beta to estrone of normal and neoplastic human breast tissue. Specific activity  of 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) was measured in 48 tissue specimens of human female breast cancer and, in addition, 48 nonmalignant tissue specimens obtained in each case from the same cancer-bearing breast. In all cases the nonmalignant tissue showed greater conversion of estradiol-17 beta into estrone than the neoplastic tissues. In normal human breast tissue of premenopausal women specific enzyme activity depended on the phase of the MENSTRUAL CYCLE: the highest values of 17 beta-HSD activity were found in the early secretory phase. To determine the intracellular distribution of the 17 beta-HSD, purified microsomes, mitochondria, peroxysomes, lysosomes, nuclei and cytosol fractions were prepared. The purity of each fraction was monitored by marker enzymes. It was found that the 17 beta-HSD was mainly located in mitochondria and microsomes. Furthermore it could be demonstrated that the microsomal enzyme was bound tightly to the membranes of the endoplasmic reticulum, while the mitochondrial 17 beta-HSD was mainly associated with the outer membranes of the organelle. Kinetic parameters (Km-values, coenzyme requirements and maximal velocities) of a cytoplasmic, nuclear, mitochondrial and microsomal 17 beta-HSD of normal and neoplastic human mammary tissue were compared. Maximal velocity was highest in enzyme preparations of normal mammary tissue obtained from premenopausal women in the early secretory phase. Km-values wrere nearly identical in normal and neoplastic mammary tissue preparations (approx. 1 X 10(-6) M). NAD was more efficient than NADP as a cofactor. For the conversion of estradiol to estrone the optimum temperature was approximately 40 degrees C and the optimum pH 9.5. For the reduction of estrone the optimum pH was 6.5. Sulphydryl groups were shown to be essential for catalysis.


Back-diffusion--fact or fiction?

Back-diffusion--fact or fiction? Alterations in the concentration of acid in gastric juice secreted at different flow rates and disappearance of acid from the gastric lumen, when the gastric mucosa is exposed to acid luminal contents, have been interpreted as indicating "back-diffusion" of acid into the gastric mucosa from the luminal contents. The loss of acid from the gastric contents increases when the mucosa is exposed to certain drugs or is diseased, giving rise to the suggestion that the increased degree of "back-diffusion" of acid indicates mucosal damage, reflecting a breakdown of the gastric mucosal "barrier" to back-diffusion of acid from the gastric lumen. The change in the "barrier" properties of the gastric mucosa has been found to be associated with change in the electrical properties of the mucosa, so that alterations of the transmucosal potential difference has been considered to denote gastric mucosal damage. The case for every one of these hypotheses and for their underlying assumptions is discussed and found wanting for lack of direct evidence.


Effect of cimetidine on lower esophageal sphincter pressure, intragastric pH and serum levels of immunoreactive gastrin in man. The influence of cimetidine on the lower esophageal sphincter, the intragastric pH and the serum levels of immunoreactive gastrin was investigated in eight volunteers and compared with a control group. After oral application of 400 mg cimetidine, the intragastric pH rose from 1.7 +/- 0.13 to 6.2 +/- 0.4 and the lower esophageal sphincter pressure increased slightly but significantly from 15.6 +/- 1.1 to 22.7 +/- 1.8 mm Hg after 20 min and to 25.8 +/- 2.0 after 30 min, respectively. At the same time the serum immunoreactive gastrin levels did not change. A direct effect of cimetinidine on the lower esophageal sphincter or an indirect effect via gastric alkalinization is discussed.


Effects of posture on gastro-oesophageal reflux. Continuous oesophageal pH measurements have been used to assess the influence of posture (lying, sitting, bed-up) on gastro-oesophageal reflux. The percentage of time during which oesophageal pH was below 5 and the number of reflux episodes was significantly reduced when patients were in bed-up position than when sitting or lying. There was no significant difference when sitting and lying positions were compared. The results suggest that by adopting the bed-up position (elevation of the head end of the bed with blocks of 28 cm), the patient will have a symptomatic benefit, the frequency of reflux is decreased, and acid clearing is improved.


Effect of cimetidine on gastric mucosal histamine and histidine decarboxylase activity in rats. In conscious rats and in anaesthetized gastric fistula rats, the effects of low and high doses of the histamine H2-receptor antagonist cimetidine was studied on gastric mucosal histamine concentration and histidine decarboxylase activity with or without concomitant administration of pentagastrin. In conscious animals a singleinjection of pentagastrin reduced gastric mucosal histamine concentration and elevated histidine decarboxylase activity. This effect was not antagonized by low doses of cimetidine. High doses of cimetidine, like pentagastrin, reduced the histamine concentration and elevated the histidine decarboxylase activity. In anaesthetized rats low doses of cimetidine and reduced gastric acid secretion. The effects of cimetidine on gastric mucosal histamine and histidine decarboxylase were less pronounced than in conscious animals. The histidine decarboxylase stimulating activity of high doses of cimetidine was not abolished by gastric perfusion with acid suggesting that endogenously released gastrin is not involved. A feedback relationship between the blockade of the target organ and increased histamine biosynthesis is discussed.


Glutamine synthetase induction in embryonic neural retina. Interactions of receptor-hydrocortisone complexes with cell nuclei. In the neural retina of the chick embryo, hydrocortisone (HC) elicits differential gene expression resulting in the induction of glutamine synthetase (GS), which is an enzyme marker of differentiation in the retina. The relationship between nuclear binding of receptor-hydrocortisone (R-HC) complexes and GS induction was investigated in cultures of retina tissue from 12-day chick embryos. The number of HC binding sites in the cytoplasm was estimated as 1650+/-200 per retina cell; there are approximately 1500+/-100 acceptor sites for R-HC per retina nucleus. GS induction in the retina became detectable only after R-HC bound to more than 40% of the nuclear acceptors sites; increased binding coincided with higher induction levels, until complete site saturation was attained; Proflavine, which blocks preferentially and completely GS induction in the retina by interfering in the nucleus with the enzyme-inducing action of the hormone, reduced nuclear binding of R-HC by only 20%; thus, only part of the R-HC that binds in the nucleus appears to be directly involved in eliciting the induction of GS. Within one hour after exposure of the retina to an inducing dose of HC, there was translocation of HC and HC-receptors (as R-HC complexes) from the cytoplasm into the nucleus and saturation of nuclear accepegan to decline; in 12 h, it was reduced to 50% of the initial saturation level. Since, during this time, the enzyme activity to increase, persistence of the induced state depends on association of the hormone with only a portion of the sites in the nucleus to which it can bind. The decrease in the amount of bound HC in the nuclei of induced cells was accompanied by an increase in the level of HC receptors in the cytoplasm. About 50% of this increase could be prevented by cycloheximide; this suggests that the reappearance of HC receptors in the cell cytoplasm may be due, at least in part, to de novo synthesis of HC receptors.


Changes in the antral mucosal pepsin in dogs with chronic ulcer: pathogenesis of cinchophen ulcer. All of the dogs given continuous injection of 100 mg/kg sodium cinchophen for 21 days developed chronic ulcers in the pyloric portion of the stomach. Those dogs given cinchophen exhibited a definite increase in gastric pepsin secretion. Readings of gastric mucosal pepsinogen showed a significant high concentration both in the fundic and pyloric gland area in the cinchophen-treated animals. As the injections were continued, the gastric mucosa-juice peptic activity ratio (MJPR) in the fundic gland area become low. These results do not point to pathological changes in the fundic gland area. The mean pH value of the surface of antral mucosa varied greatly from dog to dog and was slightly higher than normal. In the dog which had chronic ulcers in the antral portion, the antral mucosal pepsinogen concentration become eight times higher than that seen in the control animals. The incidence and chronicity of the cinchophen gastric ulcers were related to the local pepsin increase adjacent to the lesions. The origin of pepsin which appeared in the antral mucosa and cinchophen ulcerogenesis were discussed.


Carcinoembryonic character of gamma-glutamyltranspeptidase in primary hepatocellular carcinoma. As a characteristic isoenzyme of gamma-glutamyl transpeptidase (gamma-GTP) has been detected in sera of patients with primary hepatocellular carcinoma, which migrates to alpha-globulin region on polyacrylamide-gel electrophoresis, biochemical studies on human fetal liver, Morris hepatoma (7316-A, 7794-A), and human hepatoma was carried out to elucidate its carcinoembryonic character. The highest distribution of the enzyme was found in particle fraction of human fetal liver as well as of Morris hepatoma, and an isoenzyme of gamma-GTP with the same electrophoretic mobility as detected in human hepatoma was obtained, which reflected to the pattern of the serum zymograms. Histochemically, the enzyme was distributed in plasma membrane of the fetal hepatocytes and Morris hepatoma cells, while it was distributed diffusely throughout the cytoplasm of human hepatoma cells. These findings may strongly suggest that gamma-GTP in hepatoma has a carcinoembryonic character and the detection of a serum isoenzyme in the alpha-globulin region is a quite diagnostic as well as the detection of alpha-fetoprotein in the field of neoplasma of the liver. The physicochemical and kinetic properties of the enzyme in human hepatoma were also discussed.


Comparison of lactulose and neomycin in the treatment of chronic portal-systemic encephalopathy. A double blind controlled trial. A randomized double blind clinical comparison of neomycin and lactulose was performed in 33 cirrhotic patients with chronic portal-systemic encephalopathy (PSE) at seven cooperating hospitals. In order to maintain double blindness, sorbitol syrup was used as a control solution along with neomycin and was compared with lactulose syrup and placebo tablets in a double drug protocol. Twenty-nine patients were studied in a crossover investigation in which each received both therapeutic regimens preceded and followed by control periods. Four additional patients received one or the other agent, but did not receive both. Serial, semiquantitative assessments were made in all patients of mental status, asterixis, and the trailmaking test (TMT) and electroencephalograms (EEG) and arterial ammonia levels. Both neomycin-sorbitol and lactulose were effective in the majority of patients (83 and 90%, respectively). Each of these parameters (mental state, asterixis, TMT, EEG, and NH3) was improved significantly by neomycin-sorbitol and lactulose. The post-treatment levels for each of these measures were similar in the neomycin and lactulose-treated groups. Mean stool pH was reduced by neomycinsorbitol to 6.1 and by lactulose to 5.5. This difference was highly significant statistically. Bowel activity was similar in the two groups. Both drugs were free of toxicity. These investigations demonstrate that both lactulose and neomycin-sorbitol are effective in the treatment of chronic portal-systemic encephalopathy.


Heartburn of pregnancy.

Heartburn of pregnancy. Lower esophageal sphincter pressure, basal gastric pH, fasting plasma gastrin, and plasma concentrations of estrone, estradiol, and progesterone were measured in pregnant volunteers at 12, 24, and 36 weeks of gestation, and again at 1 to 4 weeks postpartum. In addition, basal and pentagastrin-stimulated acid secretory responses at each time were measured. No differences in basal gastric pH, basal, and peak acid outputs were observed during pregnancy when compared to the postpartum values. In contrast, lower esophageal sphincter pressure was reduced at all times during pregnancy, reaching a nadir at 36 weeks. Postpartum lower esophageal pressures were normal. As expected, plasma concentrations of progesterone and both estrogens increased progressively during pregnancy. These data are consistent with earlier studies in women ingesting oral contraceptives. Moreover, they provide support for the thesis that the progressive increase in plasma progesterone alone or in combination with estrogens that occurs during pregnancy is responsible for the reduction of lower esophageal sphincter pressure which allows esophageal reflux to occur with the resultant development of symptomatic heartburn.


Acid secretion and serum gastrin at graded intragasric pressures in man. In 16 healthy subjects, gastric distention was produced by infusion of 5% mannitol solution, pH 5.5. Constant intragastric pressure was maintained by use of a barostat. Over successive 1-hr periods the head of pressure was raised in 5-cm increments from an arbitrary zero point to 15 cm. Gastric acid secretion was measured by constant intragastric titration. Blood samples were obtained throughout the study for measurement of serum gastrin concentrations. When intragastric pressure was raised from zero to 5 cm H2O, gastric acid secretion increased significantly (24% of peak acid response to pentagastrin). Acid responses at 10 and 15 cm pressure were lower. Serum gastrin concentrations increased slightly at 15 cm pressure but not at 5 or 10 cm. There was no correlation between increments in serum gastrin and acid secretory rates. We conclude that gastric distention at low pressures stimulated acid secretion by a mechanism and did not involve increases in circulating gastrin concentrations. Slight increases in serum gastrin observed at the highest distending pressure were not associated with further increases in acid secretion.


Diurnal variations in the pH of pathological gallbladder bile. The pH of gallbladder and common duct bile from patients undergoing surgery for cholecystectomy has been measured. The bile was collected and kept anaerobically at 37 degrees C, and the pH measured at 37 degrees C, generally within 30-60 minutes of the bile being taken from the patient. Only data from patients having functioning or poorly-functioning gallbladders were included in the calculations. The pH of common duct bile was always greater than that of the corresponding gallbladder bile, and the data available suggest that it does not vary diurnally. The mean pH of gallbladder bile from patients undergoing their operation at different times during the day shows a diurnal variation, the bile becoming more acidic with time. Furthermore, there is also a diurnal variation in the activity of the acidifying process. Data for the patients suggest this is retarded by sleep, inactivity, or lying down.


Sulphasalazine in asymptomatic Crohn's disease. A multicentre trial. During a six year period 43 patients with Crohns disease were included in a double-blind controlled trial of sulphasalazine given for one year as a possible treatment for reducing the relapse rate after resection or in asymptomatic patients with established disease. No trend in favour of sulphasalazine over the control group was observed. The difficulties of such a trial due to the small number of patients entered from nine hospitals, the varied nature of the disease, and the high incidence of complications, such as intraperitoneal abscess formation, are discussed.


Differences in the reactivities of human urokinase and the porcine tissue plasminogen activator. It has previously been shown, that large differences exist between the effects of 6-aminohexanoic acid or alpha1-antitrypsin on fibrinolysis caused by a porcine tissue plasminogen activator or by human urokinase, while insignificant differences exist between the effects of a number of natural protease inhibitors on fibrinolysis caused by the two types of plasminogen activator. The present study shows that changes in substrate composition (pH, ionic strength fibrinogen concentration, plasminogen concentration) may influence to different degrees the fibrinolytic activities of human urokinase and the porcine tissue plasminogen activator. It is suggested, that this finding is partly related to marked differences in affinity for fibrin of the two activators.


[Synthesis of norepinephrine from 3,4-dihydroxyphenylserine by L-aromatic amino acid decarboxylase of the rat brain and kidneys]. The enzymic decarboxylation of stereoisomers of DOPS was examined using rat brain and kidney decarboxylase. Optimal assay conditions for racemic threo- and racemic erythro-DOPS decarboxylation were determined by the experiments concerning 1) time course, linear for 20 min, 2) optimal pH, pH 8.2, 3) optimal temperature, 37 degrees C except racemic L-threo-DOPS decarboxylation by kidney enzyme and 4) protein concentration, 1 to 5 mg in incubation medium. Under the optimal assay condition, Km of brain enzyme for L-threo-DOPS was 1.43 X 10(-3)M and Vmax, 2.22 nmoles NE/mg/15min, and Km for racemic erythro-DOPS was 10(-3)M  and Vmas, 4.3 nmoles NE/mg/15min. Km of kidney enzyme for L-threo-DOPS was 1.37 X 10(-3)M and Vmax 21 nmoles NE/mg/15min, and Km for racemic erythro-DOPS was 8.7 X 10(-4)M and Vmax, 16.7 nmoles NE/mg/15min. On the other hand, D-threo and D-erythro-DOPS were scarcely decarboxylated. Decarboxylation of L-threo-DOPS in kidney enzyme was markedly inhibited by D-threo-DOPS. Kinetic analysis revealed that the type of inhibition was non-competitive. In helically-cut strips of isolated rabbit aorta, the contractile response to NE (10(-8)g/ml) formed from L-threo-DOPS was 95% that of 1-NE (10(-8)g/ml) while the response to NE (10(-8)g/ml) formed from racemic erythro-DOPS was not detectable. These results suggest that L-threo-DOPS is a more effective precursor of natural 1-NE than racemic threo-DOPS.


The fermentative production of oxytetracycline on industrial by-products by Streptomyces rimosus 12907. Three strains of Streptomyces rimosus were grown on four different media. The one suitable for the production of oxytetracycline by Streptomyces rimosus 12907 was modified by black strap molasses, fodder yeast (40% total protein) and rice bran. The volume of the fermentation medium was sealed up in a 1200-litre fermentor aerated with sterile air obtained from a system used in the purification of air. 850 g crude oxytetracycline was obtained when the fermented medium (700 litres) was extracted with 1-butanol.


[Congenital gastrointestinal diseases with manifestations in adulthood]. A genetic background is discussed in many disorders of the gastrointestinal tract with a disposition in addition to environmental factors. The pathophysiology of most hereditary diseases is unknown although the mode of inheritance is established. Biochemical analysis may show molecular defects or inborn lack of enzymes, cytogenetic studies may reveal chromosomal abnormalities. The knowledge of genetic factors in gastrointestinal disorders may contribute to the early detection of persons afflicted but not yet symptomatic, in some rare syndromes genetic counseling may become mandatory. Finally, there are many congenital malformations which may not cause symptoms for many years so that doubts may arise whether they are developmental anomalies or acquired conditions.


[Significance of gamma-glutamyl-transpeptidase in the diagnosis of liver diseases]. The serum levels of gamma-GT are raised early in most hepatic disorders. The highest levels usually are found in cholestasis, especially due to malignancy of the liver and the pancreas and in chronic alcoholism and drug abuse. The gamma-GT is not strictly a cholestatic enzyme. The highest score of information is yielded in alcoholic liver disease.


[Therapy of peptic ulcer and chronic pancreatitis]. Medical treatment of gastric and duodenal ulcerations has recently been improved and extended by anti-aggressive and protectively acting drugs (e.g., H2-receptor antagonists and carbenoxolone sodium). However, antacids and anticholinergic treatment are still being used in modern ulcer management. The most important therapeutical measures against  chronic relapsing pancreatitis are abstinence from ethanol and surgical treatment of biliary or pancreatic duct obstructions. Symptomatic management--pancreatic enzyme substitution and analgetics, antacids, anticholinergics--is adequate in pancreatic insufficiency and during acute exacerbation, respectively.


[Paroxysmal alveolar hypoventilation syndrome (author's transl)]. The case of a 42-year-old female patient with central disturbance of respiration was reported which, contrary to the previously described forms of central alveolar hypoventilation, could be characterized by paroxysmal-like apnoic conditions without any feeling of suffocation. Clinically, initial cardiopulmonary complications were primary in this central disturbance of respiration. The possibility of isolated apnoic paroxysms as an expression of a true cerebro-organic nature of the attacks was described. In addition, the attempt was made to localize the morphological or functional disturbance at the basis of the observed pathological process in the bulbopontine area of the brain stem on the ventral side of the medulla in the area of the point of exit of the seventh to the twelfth cranial nerves. With anticonvulsive and analeptic treatment, a distinct improvement could be observed in the disease after the cardiopulmonary complications had subsided.


[The use of beta-blocking agents in psychiatry and neurology (author's transl)]. This paper is an up-to-date review of the literature on the subject, as well as of own research. The paper discusses pharmacological and experimental data concerning the central nervous activity of beta-blocking agents. Their use in anxiolysis - in adults and children -, ethological research, their indications in the treatment of various psychoses, withdrawal syndromes of opiate, alcohol, hypnotics, tranquilizers, marihuana and amphetamine addiction, Parkinson, essential, familiar, senile and lithium induced tremors, as well as in side effects of other psychopharmacological drugs is analysed. The relevance of different studies and therapeutical indications is discussed. Finally, tha paper points to the side-effects, advantages and disadvantages of the above substances in neuro-psychiatric therapy and stresses their importance for future research.


[Purification and properties of two beta-glycosidases from Cicer arietinum L. with preferential specificity for biochanin A 7-beta-apiosylglucoside (author's transl)]. Four different beta-glycosidases have been separated from leaves of chick pea plants, Cicer arietinum L., by DEAE-cellulose chromatography. One is specific for isoflavone 7-beta-glucosides and has been described elsewhere. Two others showed very similar protein properties and identical catalytic activities. They have been further purified and both appeared as single, homogeneous protein bands after alkaline disc electrophoresis as well as isoelectric focusing. Isoelectric points are at pH 4.35 and 4,45, respectively. Both beta-glycosidases have molecular weights of 120000-140000 and have two subunits with identical molecular weights of 65 000. Both beta-glycosidases preferentially catalyze hydrolysis of diglycosides like biochanin A 7-beta-apiosyl(1 leads to 2)glucoside (Km=1.5 X 10(-4) M; V=10 mumol X min-1 X mg-1). The apiosylglucoside unit is liberated as an intact disaccharide. beta-Glucosides like biochanin A 7-beta-glucoside or 2-nitrophenyl glucoside are also efficiently hydrolyzed. These beta-glycosidases also possess transferase activity, but only when measured with isoflavone aglycones as acceptors. Transfer of the intact apiosylglucoside unit of biochanin A 7-beta-apiosylglucoside could be demonstrated. The enzymes have a pH optimum of 5.5. The beta-glycosidates are strongly inhibited by p-hydroxymercuribenzoate and Bromocondurite. Glucono-1,5-lactone, Ag and Hg2 showed only weak inhibition and Condurit B epoxide had no effect at all. A fourth beta-glycosidase activity from chick pea leaves shows no preferential activity for isoflavone 7-glycosides.


Effects of yeast proteinase A, proteinase B and carboxypeptidase Y on yeast phosphofructokinase. Incubation of a crude yeast extract containing phosphofructokinase with proteinase A, proteinase B or carboxypeptidase Y gave the following results: Proteinase B and carboxypeptidase Y did not change the activity of phosphofructokinase during incubation. On the other hand, incubation with proteinase A resulted in a 40-100% activation; continued incubation, however, led to an inactivation of the enzyme. Addition of allosteric effectors did not change the activation or inactivation process. The activated phosphofructokinase was not changed with respect to pH optimum and ATP inhibition. Molecular weight determination of phosphofructokinase in crude extracts in the presence of inhibitors of proteinase A indicated a molecular weight of 700000. Without inhibitors of proteinase A, the molecular weight was determined to be 600 000, while after 40-100% activation by proteinase A, a molecular weight of 500 000 was obtained. The activity profile of proteinase A in density gradients indicated that this enzyme is bound to variety of cellular proteins.