Choline acetyltransferase and tyrosine hydroxylase serve as enzyme markers for preganglionic and postganglionic sympathetic nerves, respectively. There is abundant evidence that experimental conditions which increase the activity of the peripheral sympathetic nervous system produce an increase in the activity of neuronal tyrosine hydroxylase and dopamine fl-hydroxylase 11. The activity of these...

Tyrosine hydroxylase, a hypoxia-regulated gene may be involved in tissue adaptation to hypoxia. Intermittent hypoxia, a characteristic feature of sleep apnea, leads to significant memory deficits, as well as to cortex and hippocampal apoptosis that are absent following sustained hypoxia. To examine the hypothesis that sustained and intermittent hypoxia induce different catecholaminergic respons...

Tyrosine hydroxylase activity is reversibly modulated by the actions of a number of protein kinases and phosphoprotein phosphatases. A previous report from this laboratory showed that low-molecular-weight substances present in striatal extracts lead to an irreversible loss of tyrosine hydroxylase activity under cyclic AMP-dependent phosphorylation conditions. We report here that ascorbate is on...

Tryptic peptide fragments of tyrosine hydroxylase isolated from 32PO4-prelabeled bovine adrenal chromaffin cells are resolved into seven phosphopeptides by reverse phase-high performance liquid chromatography. All seven of the peptides are phosphorylated on serine residues. Three of these putative phosphorylation sites, peptides 3, 5, and 6, are rapidly phosphorylated (5-fold in 15 s) by both a...

Malfunction of glutamatergic neurotransmission in postnatal period is considered to be a risk factor for development of schizophrenia. Thus, the present study investigates the impact of NMDA receptor blockade in the postnatal period on the density of tyrosine hydroxylase immunoreactive axonal arbors in the rat medial prefrontal cortex. Behavioral experiments revealed that adult rats (60 days ol...

Approximately 90% of the total tyrosine hydroxylase activity of bovine adrenal medulla homogenates was localized in the particulate fraction of the homogenate. The particulate enzyme was solubilized by incubation with trypsin, and the solubilized enzyme was partially purified. This enzyme was found to behave like the tyrosine hydroxylase which had been purified from the supernatant fraction by ...

Many inherited disorders affecting aromatic amino acid metabolism have been described. This review will concentrate on the defects that lead to deficiencies of dopamine and serotonin within the central nervous system. Phenylalanine hydroxylase, tyrosine hydroxylase, and tryptophan hydroxylase all require tetrahydrobiopterin (BH4) as a cofactor. Inherited defects that reduce the concentration of...

The effect of a number of neuroleptics and tricyclic antidepressants on the activity of rat hypothalamic tyrosine hydroxylase was studied utilizing a direct spectrophotometric method. All the neuroleptics (but not the antidepressants) were able to reverse the substrate inhibition of the enzyme occurring when the tyrosine concentration in the medium was increased. Haloperidol, haloanisone and fl...