Ghrelin has been shown to ameliorate gastric injury by several mechanisms in experimen- tal animal models. The present study aimed to investigate the effect of pretreatment with ghrelin on indomethacin-induced gastric injury in rats and the role of heme oxygenase-1(HO-1) pathway as a novel mechanism underlying the gastroprotective effect of ghrelin. In all groups studied, ulcer score (U.S), ulcer index (U.I) and preventive index (P.I) were evaluated and the gastric inflamma- tory biomarkers including levels of tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β) and myeloperoxidase (MPO) activity as well as prostaglandin E2 (PGE2), malondialdehyde (MDA), glutathione (GSH), superoxide dismutase (SOD), HO-1 and bilirubin as an indicator of heme oxy- genase activity were measured. Indomethacin induced significant elevation in U.S and U.I as well as the inflammatory and the oxidative markers and reduced the PGE2 in addition to HO-1 level and activity. Pretreatment with ghrelin reversed these results. In order to elucidate the possible role of HO-1 in mediating the protective effects of ghrelin, tin protoporphyrin (SnPP) HO-1 blocker was administrated; it significantly attenuated the gastroprotective effect of ghrelin. In conclusion HO-1 activity significantly contributes toward ghrelin-mediated gastroprotection. |
