Myocardial ischemic post-conditioning attenuates ischemia reperfusion injury via PTEN/Akt signal pathway.

OBJECTIVES

To investigate whether myocardial ischemic post-conditioning attenuates ischemia reperfusion injury via PTEN/Akt signal pathway.

DESIGN

Forty-five male Sprague-Dawley rats were randomly divided into three groups: Sham, Ischemia reperfusion (I/R) and Ischemic post-conditioning (IPost) group. After the experiment finished, myocardial infarction area was examined. Serum creatine phosphokinase and lactate dehydrogenase activity were detected at baseline and the end of reperfusion. The protein levels of PTEN, Akt, p-Akt, Bax and Bcl-2 were measured by Western blot method.

RESULTS

Myocardial infarct size was significantly reduced in IPost as compared to I/R. Results were confirmed by serum creatine phosphokinase and lactate dehydrogenase activity. In addition, PTEN and Bax protein expression were inhibited and the p-Akt and bcl-2 protein expression were enhanced in IPost compared with I/R (P < 0.05). At the same time, the ratio of Bax and Bcl-2 was decreased in IPost (P < 0.05). However, ischemic post conditioning did not affect the total Akt level (P > 0.05).

CONCLUSIONS

We confirmed that ischemic post-conditioning protects the heart against reperfusion injury. It is important that we demonstrated that the cardioprotective effect of ischemic post-conditioning was involved in the inhibition of PTEN, activation of the PI3K/Akt pathway and reduction of the cardiomyocyte apoptosis.