Effect of centrally administered prolactin on gastric and duodenal ulcers in rats

The effect of centrally administered prolactin on gastric acid secretion an d experimentally-induced gastric and duodenal ulcers was studied. The acute gastric ulcer models used were pylorus ligation, indomethacin-induced and ethanol-induced gastric ulcers. Chronic gastric ulcers were induced using a cetic acid and duodenal ulcers by cysteamine hydrochloride. In pylorus liga ted rats, prolactin (1 mug/kg icv) produced 45% increase in gastric content volume, significant increase in free acidity (P < 0.001), total acidity (P < 0.001) and ulcer index (P < 0.001). It did not show any significant effe ct on ethanol-induced and indomethacin-induced gastric ulcers. Prolactin in creased the ulcer index (P < 0.001) and ulcer score (P < 0.05) in acetic ac id-induced chronic gastric ulcers. It also increased ulcer area (P < 0.05) in cysteamine-induced duodenal ulcers. Therefore, the proulcerogenic activi ty of prolactin was due to its gastric hypersecretory effect.