Effects Of Exercise Preconditioning On Neurological Function And Protein Expression Of IFN-Γ And IL-4 In Cerebral Ischemia/Reperfusion Rats

Objective:By studying the effects of exercise preconditioning on the neurological function and expression of IFN-γ and IL-4 in brain tissue and serum in cerebral ischemia/reperfusion rats,the brain protective mechanism of exercise preconditioning was explored.Methods:Thirty-six SPF SD(Sprague-Dawley)male rats were randomly divided into three groups: sham operation group,model group and exercise preconditioning group,with 12 rats in each group(n=12).The rat middle cerebral artery cerebral ischemia/reperfusion model(MCAO/R)was established by the modified tethering method.The rats in the first two groups were not given any intervention,and the rats in the exercise preconditioning group were given electric treadmill exercise intervention for 3 weeks,and the rats in the three groups were given grasping and feeding under the same conditions.According to the modified Neurological Severity Score(m NSS),the neurological deficits of the rats were evaluated at four time points: 12 h,1d,3 d,and 7 d after reperfusion.After 7 days of reperfusion,HE staining was used to observe the pathological damage of the ischemic brain tissue in each group;The levels of IFN-γ and IL-4 in serum were detected by enzyme-linked immunosorbent assay(ELISA);The protein expressions of IFN-γ and IL-4 in the ischemic lateral brain tissue were determined by immunohistochemistry(IHC).Results:1.The modified Neurological Severity Scores(m NSS):After 12 h,1 d,3 d,and 7 d of cerebral ischemia/reperfusion,there was no neurological deficit in the sham-operated group;compared with the sham operation group,the m NSS score of the model group increased significantly(P<0.05);Compared with the model group,the m NSS score of the rats in the exercise preconditioning group was significantly decreased(P<0.05).2.HE staining:After 7 days of cerebral ischemia/reperfusion,the morphological structure of the ischemic side of the rats in the sham operated group was normal,and no obvious pathological damage was found;Compared with the sham operated group,the pathological damage of the ischemic brain tissue in the model group was significantly increased;Compared with the model group,the pathological damage of the ischemic brain tissue in the exercise preconditioning group was significantly reduced.3.The content of IFN-γ and IL-4 in serum:After 7 days of cerebral ischemia/reperfusion,the content of pro-inflammatory factor IFN-γ in serum of rats in sham operation group was the least,and the content of anti-inflammatory factor IL-4 was the highest;Compared with the sham operated group,the serum IFN-γ content in the model group increased,while the IL-4 content decreased(P<0.05);Compared with the model group,the content of IFN-γ in the serum of the rats in the exercise preconditioning group decreased,while the content of IL-4 increased(P<0.05).4.Protein expression of IFN-γ and IL-4 in the ischemic lateral brain tissue:After 7 days of cerebral ischemia/reperfusion,the average optical density(AOD)of IFN-γ in the ischemic lateral brain tissue of rats in the sham-operated group was the lowest,and the average optical density of IL-4was the highest;Compared with the sham operated group,the AOD value of IFN-γ in the ischemic lateral brain tissue of the model group was significantly increased,and the AOD value of IL-4 was significantly decreased(P<0.05);Compared with the model group,the AOD value of IFN-γ in the ischemic lateral brain tissue of the rats in the exercise preconditioning group decreased,and the AOD value of IL-4 increased(P<0.05).Conclusions:1.Exercise preconditioning can reduce the neurological deficit score in rats with cerebral ischemia/reperfusion injury,improve the pathological damage of ischemic area of cerebral ischemia in rats with cerebral ischemia/reperfusion,and exert the protective effect of cranial nerves.2.Exercise preconditioning can down-regulate the content of IFN-γ and up-regulate the content of IL-4 in brain tissue and serum in ischemic area of rats with cerebral ischemia/reperfusion injury,and resist the inflammatory injury after cerebral ischemia.