The effects of Leptin on gastric ulcer due to physical and psychological stress: Involvement of nitric oxide and prostaglandin E2

The present study aimed to assess the effects of Leptin on physical and psychological stresses inducing gastric ulcer. The potential role of endogenous nitric oxide (NO) and prostaglandin E 2 (PGE 2 ) in the effects of Leptin on the gastric ulcer in rats are also investigated. In this study, fifty-four male Wistar rats were equally divided into 9 groups and Leptin (10 µg/kg, s.c.) was administered twice a day for 14 days in advance of physical and psychological stress. Also, N G - nitro-l-arginine-methyl ester (L-NAME, 10 mg/kg, an inhibitor of NO synthase) and indomethtacin (5 mg/kg, in order to inhibit PG synthesis) were applied before Leptin administration. Ulcer index, gastric acid secretion, NO metabolites and PGE 2 of stomach tissue suspension were all measured. Results indicated that ulcer index and gastric acid secretion were significantly decreased (p<0.05) in Leptin in compare with those of single stress groups. Also, NO metabolites and PGE 2 were increased (p<0.05) in Leptin groups than both L-NAME and Indomethacin+Leptin groups. Conclusively, data of this study emphasized the healing ability of Leptin on gastric ulcer induced by physical and psychological stresses involves the NO and PGE 2 pathways.