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Biomedical subjects

H Viveros

Publications and source records attributed to H Viveros.

5 recordsLinked to original sources
PubMed1978

Chronic effects of nicotine on catecholamine synthesizing enzymes in rats.

The effects of chronic administration of nicotine upon catecholamine (CA) synthesizing enzymes of rat hypothalamus, striatum and adrenal medulla were studied. Nicotine 3 mg/kg/day for 14 days, increased tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH) in hypothalamus and adrenal medulla but did change striatum TH. The data suggest that chronic nicotine administration can produce similar long-term alterations in both of the main CA forming enzymes in the hypothalamus and in adrenal medulla.

Adrenal Medulla↗
PubMed1976

NIH conference. Dopamine- -hydroxylase. Basic and clinical studies.

Dopamine-beta-hydroxylase, the enzyme responsible for conversion of dopamine to norepinephrine, is released along with catecholamines from the adrenal medulla and from sympathetic nerve endings. The properties and mechanisms of the enzyme's action are discussed and its distribution described. Dopamine-beta-hydroxylase is a valuable indicator of exocytosis as a mechanism for neurotransmitter release. The enzyme is present in plasma, but its levels vary widely between individuals. This variation seems to be related more to genetic factors than to sympathetic nerve activity. Abnormally high or low plasma levels are associated with several diseases. However, the relation of these levels to disease pathogenesis rather than to genetic determinants is unclear. Levels of the enzyme are elevated in patients with pheochromocytoma and decline after removal of the tumor. Dopamine-beta-hydroxylase levels seem to be normal in hypertensive patients. Inhibition of dopamine-beta-hydroxylase provides a useful pharmacologic approach to evaluating the role of norepinephrine in psychiatric disorders.

Adolescent↗