Gastric antisecretory and antiulcer activity of oxytocin in rats and guinea pigs

The effect of oxytocin (1 mg/kg s.c) on gastric acid secretion and on diffe rent experimentally induced gastric and duodenal ulcers was studied. The ac ute gastric ulcer models used were pylorus ligation, indomethacin, ethanol and histamine induced acute gastric ulcers. Chronic gastric ulcers were ind uced using acetic acid and duodenal ulcers by cysteamine hydrochloride. Oxy tocin showed significant antisecretory and antiulcer activity in pylorus li gated rats. Similarly oxytocin reduced the ulcer index in histamine induced gastric ulcers in guinea pigs and cysteamine induced duodenal ulcers in ra ts. The antiulcer and antisecretory effect was comparable to that of raniti dine (50mg/kg, i.p) though less in intensity. However, it did not show any gastric cytoprotective effect in ethanol and indomethacin induced ulcer mod els but ranitidine showed protection (p <0.05) in later model. Oxytocin enh anced gastric ulcer healing in acetic acid induced chronic gastric ulcer mo del. The reversal of oxytocin effect by atosiban, an oxytocin receptor anta gonist indicates a role for oxytocin receptors. The antiulcer activity of o xytocin can be attributed to its antisecretory effect. (C) 2001 Elsevier Sc ience Inc. All rights reserved.