title: Effects of a proton pump inhibitor, omeprazole, on gastric secretion and gastric and duodenal ulcers or erosions in rats.
abstract: The effects of omeprazole, a proton pump inhibitor, on gastric secretion and gastric or duodenal ulcers or erosions in rats were studied. Omeprazole, given intraduodenally, dose-dependently inhibited the gastric secretion (volume, acid and pepsin output) of pylorus-ligated rats. The antisecretory activity of omeprazole at 100 mg/kg persisted for 14 hr after treatment. Acutely induced gastric ulcers or erosions such as Shay ulcers, water-immersion stress-, indomethacin-, aspirin-, or prednisolone-induced erosions were all markedly inhibited by oral or intraduodenal administration of 10-100 mg/kg of omeprazole. The development of duodenal ulcers and gastric erosions caused by mepirizole was also potently inhibited by omeprazole at 3-10 mg/kg given orally. Repeated administration of omeprazole, 200 mg/kg/day in two divided doses for 14 days, significantly accelerated the spontaneous healing of acetic acid-induced gastric ulcers. The mechanism by which omeprazole inhibits the development of acute ulcers and accelerates healing of preexisting ulcers appears to be mainly due to its potent and long-lasting antisecretory activity. The antisecretory and antiulcer activities of omeprazole are equal to or exceed those of cimetidine, both in the maximum inhibitory response and ED50 values.
mesh_terms: D000818:Animals; D001241:Aspirin; D001562:Benzimidazoles / Q000494:pharmacology*; D055598:Chemical Phenomena; D002621:Chemistry; D004381:Duodenal Ulcer / Q000188:drug therapy*; D004840:Epirizole; D005750:Gastric Juice / Q000187:drug effects* / Q000378:metabolism; D007213:Indomethacin; D008297:Male; D009853:Omeprazole; D011239:Prednisolone; D051381:Rats; D011919:Rats, Inbred Strains; D013276:Stomach Ulcer / Q000139:chemically induced / Q000188:drug therapy*
chemical_list: D001562:Benzimidazoles; D004840:Epirizole; D011239:Prednisolone; D009853:Omeprazole; D001241:Aspirin; D007213:Indomethacin