| Objiective: To observe the effects of exercise preconditioning on cerebral infarction volume,neurobehavioral and protein expression of Parkin and LC3 in rats with cerebral ischemic stroke,and to explore the role of autophagy in the process of cerebral ischemic stroke in rats with exercise preconditioning.Methods: Eighty healthy male Sprague-Dawley rats were randomly divided into none-exercise group(C;n=40)and exercise group(M;n=40).The M group performed a 1-week adaptive exercise,and after 1 week,the C group was randomly divided into the sham group(SS;n=20)and the Middle Cerebral Artery Occlusion-Reperfusion model(MCAO-Rep)group(CM;n=20),The exercise group was divided into the exercise-control group(P;n=20)and the exercise preconditioning + MCAO-Rep group(EM;n =20).Rats in group P and EM were trained for 4 weeks without weight-bearing treadmill,setting the treadmill speed to 30 m/min,and the exercise for 6 days per week.After 1 week of adaptive feeding in the SS group and the CM group,the same water and food were given to the M group to control the body weight.Body weight of each group of rats was measured daily.Four weeks later,cerebral ischemic stroke reperfusion model was performed by MCAO-Rep in CM and EM rats,and neurobehavioral scores were performed 24 hours after reperfusion;SS and P groups were fully exposed to the middle cerebral artery but not performed by MCAO.After reperfusion for 24 hours,the brain was inoculated with TTC staining to determine the volume of cerebral infarction;HE staining,TUNEL staining was used to observe thechanges of brain structure in rats with cerebral ischemic stroke;immunohistochemistry was used to detect Parkin levels in the brain;immunoblotting was used to determine the the expression of LC3 and Parkin in brain.Results:(1)After 4 weeks,there was no significant change in body weight between the rats in the exercise group and the control group.The neurobehavioral scores showed that the rats in the CM group were significantly higher than the rats in the SS group.The TTC staining showed that the rats in the CM group and the EM group were affected.Significant infarction occurred in the lateral brain;(2)TTC staining was used to determine the percentage of infarct volume,neurobehavioral score was used to measure the changes of brain function,HE staining,TUNEL staining was used to detect the pathological level of brain,and these results show that CM group performed obvious infarction volume,neuron and tissue necrosis,apoptosis in the affected brain.,in which EM group has been improved in the affected brain;(3)Compared with the SS control group,the expression of Parkin protein in the brain of the P group increased,ischemia Parkin protein expression decreased after stroke,but EM group was higher than CM group;(4)Compared with SS,the expression of LC3-? in the ischemia penumbra of brain infarction in group P and EM group and there was no significant change in the ratio of LC3-?/LC3-?.The expression of LC3-? and LC3-?/LC3-? in brain of CM group were significantly decreased.Compared with CM group,the expression of LC3-? in brain of EM group and the LC3-?/LC3-? ratio was significantly increased.Conclusion:(1)Exercise preconditioning can reduce the neurological damage and apoptosis caused by ischemia-reperfusion,and exercise preconditioning can significantly reduce the infarct area of the ischemic reperfusion half-brain.(2)The level of autophagy decreased after cerebral ischemia-reperfusion injury.Exercise preconditioning may increase the level of autophagy in the ischemic penumbra by up-regulating the expression of parkin,and accelerate the clearance of harmful substances,thereby alleviating cerebral ischemia-reperfusion injury. |
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