Effects Of Exercise Pretreatment On Expression Of MitoKATP Channel Protein Kir6.2 And SUR1 In Cerebral Ischemia Reperfusion Rats

Objective:To investigate the effects of exercise preconditioning on the expression of mitoKATP channel protein Kir6.2 and SUR1 in brain tissue of rats with cerebral ischemia and reperfusion,and to elucidate the mechanism of brain protection.Methods:Thirty-six rats were randomly divided into model group,sham operation group and exercise pretreatment group(n = 12).The model of cerebral ischemia/reperfusion(I/R)injury was established by modified suture method.The neurological impairment was evaluated by neurological deficit score at 2 h,12 h and 24 h after ischemia and reperfusion.The morphological changes of ischemic cortex in each group were observed by HE staining.The expression of mitriKATP channel protein kir6.2 and SUR1 protein were detected by western blot.The expression of rirp protein was detected by TUNEL staining.Expression of neuronal apoptosis in cortical neurons of ischemic.Results:1.Neurological deficit score:Compared with the sham operation group,the neurological deficit score of the model group was lower than that of the sham operation group at 2h,12h and 24h after cerebral ischemia and reperfusion.The difference was statistically significant(P<0.01).Compared with the model group,the scores of neurological deficits in the exercise pretreatment group were significantly lower than those in the model group(P<0.05).The scores of neurological deficits in the model group were significantly lower than those in the model group was statistically significant(P<0.05).2.Histopathological changes:After 24 hours of cerebral ischemia and reperfusion,the brain tissue structure of the sham operation group was clear and the morphology and structure of the neurons were normal.The cortical lesions in the ischemic area of the model group were found to be interstitial edema,Neuronal cell arrhythmia,vacuolar changes were obvious,deepening of the nucleus and so on,the inflammatory infiltration around the ischemic area was obvious.Compared with the model group,the pathological damage of the brain tissue was reduced,the edema and inflammatory infiltration were Mitigation,the number of neurons has increased,deformation,necrotic neurons corresponding reduction.3,The expression of kir6.2 and SUR1 protein in ischemic penumbra were significantly higher than those in sham operation group(P<0.05).Compared with the model group,the level of Kir6.2 and SUR1 protein in the pretreatment group were significantly lower than those in the model group(P<0.05).4.Ischemic penumbra neuronal apoptosis:After cerebral ischemia and reperfusion for 24 h,compared with the model group,the number of TUNEL positive cells in the model group was significantly lower than that in the model group(P<0.05),and the difference was statistically significant(P<0.05).Conclusions:1.Exercise Preconditioning can reduce neurological deficit score,reduce ischemic cortical area pathological damage,reduce cerebral ischemia/reperfusion injury in rats nerve function.2.Exercise Preconditioning can down-regulate the expression of Kir6.2 and SUR1 proteins in the ischemic penumbra of rats with cerebral ischemia/reperfusion,and inhibit the neuroprotective effect of ischemic neurons.