Dopamine in Human Gastric Juice Determined by a Sensitive Double-Isotope-Derivative Technique

Abstract

Dopamine was measured in human gastric juice by a sensitive enzymatic double-isotope-derivative technique. Two normal subjects and two patients with a duodenal ulcer were examined before and after injection of peptavlon. Four subjects who had previously undergone a selective gastric vagotomy were studied before and after injection of insulin. During basal conditions human gastric juice dopamine concentration averaged 5.41 ± 1.67 ng/ml (± S.D.). There was no change in gastric juice dopamine after stimulation with peptavlon or insulin. In other experiments dopamine was measured in the secretion from Heidenhain pouches in dogs. The dopamine concentration in the fasting secretion was approximately the same as that observed in man. After food stimulation in the main stomach the total amount of dopamine secreted from the Heidenhain pouches increased considerably, mainly due to an eight- to fourteen-fold increase in dopamine concentration. Dopamine in peripheral venous blood in the dogs did not change during food stimulation. It is concluded that dopamine is present in fairly large amounts in human gastric juice during basal conditions. The experiments in the dogs indicate that dopamine in the gastric juice is not solely of dietary origin.

Key Words:

• Blood
• catecholamines
• dopamine
• gastric juice
• Heidenhain pouch