Antrum participates in the postprandial augmentation of the acid response to exogenous gastrin in conscious cats.

A humoral mechanism, potentiating the maximal acid, but not the pepsin response to exogenous gastrin in cats, is activated by protein-rich food in the stomach or duodenum, but not in the jejunum. In the present study, the effect of an oral meat meal on the maximal acid response to pentagastrin was investigated in Heidenhain pouch (HP) cats, and in antrectomized HP cats with duodenal exclusion and gastrojejunostomy Rouxen-Y. Antrectomy and duodenal exclusion abolished the postprandial HP acid response, and feeding did not potentiate the acid response to pentagastrin. The finding suggests that the gastrin-potentiating mechanism in the stomach is localized in the antrum, and it cannot be demonstrated in the jejunum. The basal plasma levels of gastrin and somatostatin did not differ in antrectomized and non-antrectomized cats. Antrectomy and duodenal exclusion abolished the postprandial gastrin and somatostatin responses. The plasma somatostatin increase during pentagastrin infusion persisted after antrectomy and duodenal exclusion. It is concluded that the antrum is not mandatory for the basal plasma levels of gastrin and somatostatin, but the postprandial gastrin response is of antral origin and may release somatostatin. Pentagastrin infusion releases extra-antral somatostatin in cats.