The Effect of Nicorandil on Small Intestinal Ischemia–Reperfusion Injury in a Canine Model

Background It has been shown that nicorandil, which has both ATP-sensitive K + (K ATP ) channel opener-like and nitrate-like properties, has an organ-protective effect in ischemia–reperfusion injury in several experimental animal models. Aims We evaluate the effectiveness of nicorandil on warm ischemia–reperfusion injury of the small intestine in a canine model. Methods Eighteen beagle dogs were divided into three groups: the control group ( n = 6); the nicorandil group ( n = 6), to which nicorandil was injected intravenously before the ischemia; and the glibenclamide group ( n = 6), to which glibenclamide, which closes the K ATP channel and does not suppress the nitrate effect of nicorandil, was orally administered, and then nicorandil was injected in the same manner as in the nicorandil group. Both the superior mesenteric artery and vein were clamped for 2 h. Superior mesenteric artery blood flow, small intestinal mucosal tissue blood flow, intramucosal pH, and histopathological analyses were compared among the three groups. Results Superior mesenteric artery blood flow, mucosal tissue blood flow and pHi after reperfusion were significantly maintained in the nicorandil in comparison with the control and the glibenclamide groups. The histopathological findings showed less severe mucosal damage after reperfusion in the nicorandil group compared with the other two groups. Between the control group and the glibenclamide group, no significant differences were observed in all those parameters. Conclusion This study suggests that nicorandil has a protective effect on small intestinal IR injury, and activation of K ATP channels plays an important role in inhibiting small intestinal IR injury.