Abstract: Objective To observe the effect of microinjection of oxytocin (OT) into paraventricular nucleus (PVN) on gastric ischemia-reperfusion (GI-R) injury and its local molecular mechanism. Methods GI-R injury was induced in rats by clamping the celiac artery for30 min and then reperfusing for 1 h. A cannula was inserted into the unilateral PVN for microinjection of OT. The gastric mucosal injury index was counted grossly. The expressions of Akt and caspase-3 in rat gastric mucosa were examined by Western blot and by immunohistochemistry. Results Microinjection of OT into PVN dose-dependently attenuated gastric mucosal injury subjected to GI-R. Microinjection OT into PVN significantly increased the expression of Akt protein and decreased the level of caspase-3 in gastric mucosal following GI-R. The effects of OT were prevented by pretreatment with OT receptor antagonist atosiban into the lateral cerebral ventricle. Conclusion Microinjection of OT into PVN significantly protected against GI-R injury. These central effects of OT are mediated by its receptors. The local mechanisms were mediated by increasing Akt expression, which in turn leads to inhibit caspase-3 expression.

Key words: gastric ischemia-reperfusion (GI-R), paraventricular nucleus (PVN), oxytocin (OT), Akt