Effect of PI3K-Akt signaling pathway on openness degree of mitochondrial permeability transition pore in aged model rats of myocardial ischemic preconditioning / 吉林大学学报(医学版)

ABSTRACT

Objective: To study the effect of PI3K-Akt signaling pathway on the openness degree of mitochondrial permeability transition pore (mPTP)in the aged model rats of myocardial ischemic preconditioning (IPC),and to clarify its possible mechanism.Methods:Thirty-five Wistar Wistar rats (aged 21-23 months)were randomly divided into ischemia reperfusion (I/R)group,I/R+Wort (Wortmannin,inhibitor of PI3K)group,IPC group and IPC+ Wort group (n=7).The models of I/R and IPC were established and 0.6 mg·kg-1 Wort were injected to the caudal veins of the rats in Wort group before reperfusion. After 120 min reperfusion, the myocardium tissue protein was extracted, and the Akt and p-Akt protein expression levels were detected by Western blotting method.The myocardial mitochondrial of rats was separated through differential centrifugation, and the superoxide level, SOD level and openness degrees of mPTP were determined by microplate reader. Results:Compared with I/R group (0.288±0.071),the expression level of p-Akt protein in myocardium tissue of the rats in IPC group (0.346±0.051)was increased (P 0.05).Compared with I/R group (1.15±0.15),the SOD activity in mitochondrial of the rats in IPC group (1.39±0.14)was increased (P 0.05).Compared with I/R group,the mPTP openness degree in IPC group was decreased (P 0.05).Compared with IPC group,the mPTP openness degree in IPC+ Wort group was increased (P < 0.05).Conclusion:The IPC of aged rats can inhibit the openness of mitochondrial permeability transition pore through activating the PI3K-Akt signaling pathway.