Intraduodenal lipid does not inhibit acid secretion in OLETF rats not expressing CCK-A receptor gene.

Gastric acid secretion in response to pylorus-ligation and duodenal fat feeding in Otsuka Long-Evans Tokushima Fatty (OLETF) rats without cholecystokinin-A receptor was examined. Acidity of gastric juice obtained from pylorus-ligated OLETF rats was significantly lower than that of control LETO rats. Gastric acid secretion in response to bethanechol, pentagastrin, or atropine was maintained in both OLETF and LETO rats. Intraduodenal lipid injection strongly inhibited gastric acid secretion in control LETO rats. In contrast, administration of lipid into the duodenum failed to inhibit acid secretion in OLETF rats. These results suggest that basal gastric acid secretion may be impaired in OLETF rats and that the cholecystokinin-A receptor is involved in lipid-induced acid inhibition.