Sources and Physiological Significance of Plasma Dopamine Sulfate

Dopamine in the circulation occurs mainly as dopamine sulfate, the sources and physiological significance of which have been obscure. In this study, plasma concentrations of dopamine sulfate were measured after a meal, after fasting for 4 days, and during iv L-DOPA, nitroprusside, or trimethaphan in...

Full description

Saved in:

Bibliographic Details
Published in:	The journal of clinical endocrinology and metabolism Vol. 84; no. 7; pp. 2523 - 2531
Main Authors:	Goldstein, David S, Swoboda, Kathryn J, Miles, John M, Coppack, Simon W, Aneman, Anders, Holmes, Courtney, Lamensdorf, Isaac, Eisenhofer, Graeme
Format:	Journal Article
Language:	English
Published:	Bethesda, MD Endocrine Society 01-07-1999
Subjects:	Adult Aminoacids, peptides. Hormones. Neuropeptides Analytical, structural and metabolic biochemistry Aromatic-L-Amino-Acid Decarboxylases - deficiency Arteries Autonomic Nervous System Diseases - blood Biological and medical sciences Blotting, Western Dopamine - analogs & derivatives Dopamine - blood Dopamine Agents Fasting Female Food Fundamental and applied biological sciences. Psychology Gastrointestinal Neoplasms - blood Gastrointestinal Neoplasms - surgery Humans Levodopa - administration & dosage Levodopa - blood Male Nitroprusside - administration & dosage Portal Vein Proteins Trimethaphan - administration & dosage United States North America America Human Dopamine Distribution Biosynthesis Physiology Sulfates Biological activity Feeding Blood plasma
Online Access:	Get full text
Tags:	Add Tag No Tags, Be the first to tag this record!

Description
Summary:	Dopamine in the circulation occurs mainly as dopamine sulfate, the sources and physiological significance of which have been obscure. In this study, plasma concentrations of dopamine sulfate were measured after a meal, after fasting for 4 days, and during iv L-DOPA, nitroprusside, or trimethaphan infusion in volunteers; after dopamine infusion in patients with l-aromatic-amino-acid decarboxylase deficiency; in arterial and portal venous plasma of gastrointestinal surgery patients; and in patients with sympathetic neurocirculatory failure. Meal ingestion increased plasma dopamine sulfate by more than 50-fold; however, prolonged fasting decreased plasma dopamine sulfate only slightly. L-DOPA infusion produced much larger increments in dopamine sulfate than in dopamine; the other drugs were without effect. Patients with l-aromatic amino acid decarboxylase deficiency had decreased dopamine sulfate levels, and patients with sympathetic neurocirculatory failure had normal levels. Decarboxylase-deficient patients undergoing dopamine infusion had a dopamine sulfate/dopamine ratio about 25 times less than that at baseline in volunteers. Surgery patients had large arterial-portal venous increments in plasma concentrations of dopamine sulfate, so that mesenteric dopamine sulfate production accounted for most of urinary dopamine sulfate excretion, a finding consistent with the localization of the dopamine sulfoconjugating enzyme to gastrointestinal tissues. The results indicate that plasma dopamine sulfate derives mainly from sulfoconjugation of dopamine synthesized from L-DOPA in the gastrointestinal tract. Both dietary and endogenous determinants affect plasma dopamine sulfate. The findings suggest an enzymatic gut-blood barrier for detoxifying exogenous dopamine and delimiting autocrine/paracrine effects of endogenous dopamine generated in a“ third catecholamine system.”
Bibliography:	ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23
ISSN:	0021-972X 1945-7197
DOI:	10.1210/jcem.84.7.5864