The effect of mTOR in ischemic postconditioning-induced attenuation of ischemia/reperfusion injury in rat skeletal muscle

Objective To study the expression and effect of mammalian target of rapamycin (mTOR) on rat skeletal muscle ischemia-reperfusion(I/R) treated by ischemic postconditioning (I-postC). Methods Forty-eight healthy male Wistar rats were randomly divided into three groups (n=16):I/R group(4-hour ischemia/12-or 24-hour reperfusion),ischemic preconditioning(IPC)group (3 cycles of 5-minute ischemia /5-minute reperfusion) and I-postC group(3 cycles of 1-minute reperfusion/l-minute ischemia). I/R of right hind limb was induced by clamping the right femoral artery,in each group the left hind limb (the femoral artery was no clamping) as controll. The tissue morphology,wet-to-dry weight (W/D) ratio,malondialdehyde (MDA),myeloperoxidase (MPO) and expression of mTOR in skeletal muscle were and detected compared in the 3 groups.Results In I-postC and IPC group,the edema,MDA and MPO of skeletal muscle decreased significantly compared with I/R group (P0.05). There was no significant difference between the I-postC and IPC group(P0.05).Compared with I/R group,expression of mTOR increased significantly in I-postC and IPC group(P0.05) Conclusions I-postC can attenuate I/R injury of the hind limbs in rats,which may be accomplished by activation of mTOR signal pathway. The mechanism of the effect of I-postC my by as the same as IPC.