Down-Regulation of Cyclooxygenase-2 is Involved in Ischemic Postconditioning Protection Against Renal Ischemia Reperfusion Injury in Rats

Ischemic postconditioning (IPostC) is a phenomenon whereby rapid intermittent interruptions of blood flow in the early phase of reperfusion protect an organ from ischemia-reperfusion injury. In the present study, we investigated whether the protective effect of IPostC was associated with the cyclooxygenase-2 (COX-2) pathway by evaluating its expression following renal ischemia-reperfusion in rats. Animals underwent 45 minutes of renal pedicle occlusion followed by reperfusion for 1.5, 3, 6, 12, or 24 hours. IPostC was performed by six 10-second cycles of reperfusion and 10 seconds of renal pedicle occlusion at the end of ischemia. Blood and kidney samples were collected at each reperfusion time point. The protein expression of COX-1 and COX-2 were evaluated by Western blotting. Our data showed that IPostC attenuated the renal dysfunction and decreased COX-2 expression induced by ischemia-reperfusion insults. The results indicated that the protective effect of IPostC was related to down-regulation of COX-2 expression.