Dopamine Receptors do not Influence β₂-Sympathomimetic-Mediated Inhibition of Gastric Acid Secretion in the Dog

Abstract

The effect of dopamine blockade by haloperidol and metoclopramide on β₂-adrenergic-induced changes of acid secretion and pulse rate was studied in conscious gastric fistula dogs. Neither haloperidol (0.15 mg/kg and 0.60 mg/kg) nor metoclopramide (0.25 mg/kg and 1.0 mg/kg), given intravenously, had a significant influence on β₂-adrenergic-induced inhibition of gastric acid secretion or tachycardia. Dopamine blockade had no influence on pentagastrin-stimulated gastric acid secretion, but it increased pulse rate. It is concluded that dopamine receptors are not involved in the inhibiton of acid output or tachycardia induced by β₂-sympathomimetics, and dopamine is probably not a neurotransmitter for these effects.

Key-words:

• Dog
• dopamine blockade
• gastric secretion
• pentagastrin
• sympathomimetic