Exercise Preconditioning Regulates The Effects Of EPO On Cerebral Ischemia-reperfusion Injury And Cell Apoptosis In Rats

Objective:Observe the effect of exercise preconditioning on the content of EPO in serum and brain tissue after cerebral ischemia-reperfusion,to explore the protective effect of EPO-mediated apoptosis pathway in cerebral ischemia-reperfusion injury after exercise preconditioning.Methods:SD rats were randomly divided into control model group(CM group)and sham surgical group group(SS group),exercise pretreatment group(EM group)and pure exercise group(P group).After adaptive feeding,EM group and P group performed a one week of adaptive exercise.And then all the groups performed a 4-week treadmill running.After 4 weeks,the cerebral ischemia-reperfusion model was prepared using the Longa suture method.After 24 hours,the neurobehavioral score was taken to test if the model was successful,then draw the materials.Part of animals were taken the whole brain for TTC staining,the volume of cerebral infarction,HE staining used to detect pathological changes of cortex,TUNEL used to detect apoptosis,Elisa used to detect EPO content in serum.EPO,Caspase-3 and other protein contents were detected in the cerebral ischemic penumbra and observe EPO-mediated apoptosis.Results:(1)Neurological function score: After 24 hours of modeling,the nerve function of the SS group was normal.The mNSS score of the CM group was significantly higher than that of the SS group(P<0.05).Compared with the CM group,the mNSS score of the EM group was significantly lower(P<0.05);(2)TTC detection of cerebral infarction volume in rats: Compared with CM group,TMC staining infarct volume was smaller in EM group(P <0.05).(3)Pathological changes of cerebral ischemic cortex in each group: There was no obvious pathological change in SS group and P group,suggesting that treatment of P group had no obvious damage to the brain tissue;compared with SS group,Large-scale infarction of animal brain tissue in CM group suggested that the model of cerebral infarction injury was successfully constructed.Compared with CM group,the morphology of neurons in the infarct zone(sub-dark zone)of EM group was relatively normal,and the degree of lesion was significantly reduced,suggesting that the treatment of EM group had a certain improvement effect on the penumbra neuron lesions in the brain tissue of the cerebral infarction injury model animal in this experiment;(4)TUNEL detection of brain cell apoptosis in each group: Compared with SS group,the percentage of apoptosis in brain tissue of group P was not much different(P>0.05),suggesting that the apoptosis of brain tissue in group P was not obvious;Compared with the SS group,the percentage of apoptosis in the brain tissue of the CM group was significantly increased(P<0.01),suggesting that the apoptosis ofthe brain tissue in the CM group was severe.Compared with the CM group,the percentage of apoptosis in the brain tissue of the EM group was significantly lower.(P<0.05),suggesting that the apoptosis of brain tissue in the EM group is improved;(5)Western blot analysis of the content of Caspase-3 protein in the penumbra after cerebral ischemia-reperfusion injury: cerebral ischemic penumbra The results showed that only a small amount of the apoptosis-related factor Caspase-3 was found in the SS group,and a small amount of Caspase-3 protein was also observed in the P group.Compared with the SS group,the expression of Caspase-3 protein in the brain of the CM group was significantly increased(P<0.01).Compared with the CM group,the expression of Caspase-3 protein in the brain of the P group and the EM group was significantly decreased(P< 0.01);(6)Immunohistochemical detection of caspase-3protein expression in the brain of each group showed that the negative cells were blue,the substrate was white,the positive cells were yellow or brown,and the Caspase-3positive products were mainly distributed in the nucleus.In the cytoplasm.Compared with the SS group,the Caspase-3 protein content in the CM group was significantly increased(P<0.01);the Caspase-3 protein content in the P group was unchanged(P>0.05);compared with the CM group,the Caspase-3 protein content in the EM group was compared.(P<0.05);(7)Elisa showed serum EPO content: compared with SS group,serum EPO protein expression was significantly decreased in CM group and EM group(P<0.01);compared with group P,CM group The expression of EPO protein in serum of rats was significantly decreased(P<0.01).The expression of EPO protein in serum of EM group was decreased(P<0.05).Compared with CM group,the expression of EPO protein in serum of EM group was significantly increased(P<0.01).(8)Western blot analysis of the EPO protein content in the penumbra after cerebral ischemia-reperfusion injury: Compared with the SS group,the expression of EPO in the brain of the CM group was significantly increased(P<0.01);compared with the CM group,the EM group The expression of EPO in the brain was decreased(P<0.05).Conclusions:(1)Four-week exercise preconditioning can significantly improve cerebral ischemia-reperfusion injury,reduce neurological impairment after cerebral ischemia-reperfusion,reduce cerebral infarction area and expression of apoptotic protein Caspase-3,alleviate apoptosis of rat brain cells,increase serum EPO content and brain EPO content after stroke.;(2)Four-week exercise preconditioning may play a neuroprotective role in cerebral ischemia-reperfusion injury by regulating the EPO content in serum and brain tissues.