Bromocriptine Potentiation of Gastric Acid Secretion in Cats

Abstract

Bromocriptine administered both orally and intravenously potentiated gastric acid secretion in response to submaximal pentagastrin stimulation in cats. Bromocriptine did not increase the maximum acid secretion in response to pentastrin, not did it stimulate basal acid secretion. Potentiation was observed in normal and vagotomized animals which precludes involvement of the vagi in the response. The mechanism of action of this compound on the stomach does not appear to be mediated through stimulation of dopaminergic receptors as no potentiation was observed with dopamine infusions. It is argued that the bromocriptine potentiation of gastric acid secretion may be a demonstration of 5-hydroxytryptamine or alpha-adrenergic antagonism. However, the potentiation observed with daily oral bromocriptine treatment had disappeared by the eighth day and may correlate with the disappearance of gastric side effects noted in patients on bromocriptine treatment.

Dopaminergic control of gastric acid and gastrin secretion in man: lack of effects after acute oral administration of ibopamine, an analogue of dopamine.

“…High doses of bromocriptine and lergotrile, which stimulate dopamine receptors in the periphery as well as in the central nervous system, reduce gastric acid secretion in the rat (Szabo, 1979), whereas lower doses have an opposite effect both in man (Caldara et al, 1978b) and in the cat (Hirst et al, 1976). The lack of changes in gastric acid secretion in normal volunteers after ibopamine is not easily explained.…”

“…It was shown that dopamine infusion, a drug which does not cross the blood-brain barrier, inhibits gastric acid secretion in man (Caldara et al, 1978a;Valenzuela et al, 1979), while either a decrease or no changes were reported in the animal, possibly due to the different doses employed (Hovendal et al, 1982;Valenzuela & Grossman, 1976). High doses of bromocriptine and lergotrile, which stimulate dopamine receptors in the periphery as well as in the central nervous system, reduce gastric acid secretion in the rat (Szabo, 1979), whereas lower doses have an opposite effect both in man (Caldara et al, 1978b) and in the cat (Hirst et al, 1976). The lack of changes in gastric acid secretion in normal volunteers after ibopamine is not easily explained.…”

Effect of dopamine infusion on gastric and pancreatic secretion and on gastrin release in man.

“…Little is known of the effects of dopamine on gastric and pancreatic secretions. Dopamine infusion has been reported to reduce submaximal pentagastrinstimulated acid secretion in the dog (Valenzuela and Grossman, 1976), but not in the cat (Hirst et al, 1976). Pancreatic secretion was increased by dopamine administration in the dog (Hashimoto et al, 1971;Valenzuela and Grossman, 1976;Bastie et al, 1977).…”