The acute activation of tyrosine hydroxylase from central catecholaminergic neurons, peripheral adrenergic neurons and adrenal medulla following nerve stimulation, stress and administration of drugs known to affect nervous function will be characterized further. Employing monospecific antibody to tyrosine hydroxylase and gel electrophoresis procedures which permit the rapid isolation of tyrosine hydroxylase from tissues, attempts will be made to determine whether the enzyme is phosphorylated as a consequence of sympathetic nerve stimulation. The role of calcium-dependent regulator protein (calmodulin, CDR) and calcium in the activation of tyrosine hydroxylase will be assessed. The effects of nerve stimulation, cyclic AMP-dependent protein kinase, phospholipid and anion activation of the enzyme will be compared in order to determine whether the molecular basis for the activation is analogous in all circumstances. Protein kinases and phosphoprotein phosphatases from adrenergic tissues will be purified and characterized and their possible relevance to the activation and deactivation of tyrosine hydroxylase will be determined. The role of cyclic AMP-independent protein kinase in the regulation of tyrosine hydroxylase in central and peripheral adrenergic tissues will be evaluated. Ultrastructural localization of tyrosine hydroxylase will be determined by immunocytochemical techniques and the anatomical relationship of tyrosine hydroxylase containing nerve terminals to cholinergic, gabaergic and peptidergic nerve terminals in the brain will be examined. Regulation of catecholamine release consequent to nerve stimulation from brain slices, brain synaptosomes and the isolated vas deferens preparation will be evaluated with particular emphasis on cyclic nucleotides, opioid agonists, beta adrenoceptors, dopamine and cholinergic agonists. The uptake of tyrosine into adrenergic neurons and the equilibration of amino acids in this structure will be assessed. Amino acid aminotransferases and keto acids will be evaluated with regard to their effects on maintenance of available neurotransmitter stores during prolonged nerve stimulation.