OBJECTIVESTo observe the effects of renal ischemic postconditioning (RI-Post) on myocardial apoptosis in rabbits with acute myocardial ischemia and reperfusion.

METHODSAll rabbits were subjected to 60 minutes ischemia by left anterior descending coronary artery occlusion (LADO) and 6 hours reperfusion. The rabbits are randomly divided into 3 groups (n = 8 in each group): (1) Ischemia-reperfusion (IR): LADO and reperfusion without additional intervention; (2) RI-Post: after 60 minutes of LADO, the left renal artery was occluded for 30 seconds and reperfused for 30 seconds and repeated 3 times, then the coronary artery was reperfused for 6 hours; (3) Medication intervention (MI): 10 minutes before coronary reperfusion, rabbits were treated with PKC antagonist GF109203X (0.05 mg/kg, IV), followed by RI-Post treatment and 6 hours coronary reperfusion. Myocardial apoptosis was measured by TUNEL and the myocardial Bcl-2 and Bax protein expressions were assessed by immunohistochemistry.

RESULTSCompared with the IR group and the MI group, myocardial apoptosis was significantly reduced (P < 0.05) and the Bcl-2 protein expression increased (P < 0.01) while the Bax protein expression decreased (P < 0.05) in the RI-Post group.

CONCLUSIONSRemote renal postconditioning applied right before the onset of coronary artery reperfusion can reduce the myocardial apoptosis induced by myocardial ischemia and reperfusion and up-regulate Bcl-2 while down-regulate Bax expression possibly by activation of protein kinase C.