| Objective:To explore the effect of exercise preconditioning on connexin 43(Cx43)and glial fibrillary acidic protein(GFAP)in rats after cerebral ischemiareperfusion,and exercise preconditioning on protein kinase C(PKC)and mltogen activated protein kinases(MAPK),protein tyrosine kinase(PTK),calmodulin(Ca M),and to elucidate the effect of exercise preconditioning on the gap junctional communication of rat glial cells after cerebral ischemia-reperfusion,and provide experimental basis for the prevention and treatment of cerebral ischemia.Experiment 1 Exercise preconditioning on the changes of Cx43 and GFAP protein in rats after cerebral ischemia-reperfusionMethod:192 rats were randomly divided into 4 groups,namely sham group,model group,EPS group,EP group,48 rats in each group,and then reperfusion for 12 hours,1 day,3 days,7 days,four time points were divided into 4 subgroups(n=12).No treatment was given to the sham group and the model group.The EPS group and the EP group were given 3 weeks of exercise preconditioning before modeling.The EPS group was modeled with the sham group,and the EP group was modeled with the model group.After successful modeling,modified neurological severity scores(m NSS)was used to evaluate the neurological deficit of rats in different groups at different time points;the expression level of Cx43 ? p-Cx43 ? GFAP protein in the semi-dark zone of cerebral ischemia was detected by Western blots method;immunofluorescence method was used to observe the average optical density value of GFAP fluorescence expression in cerebral ischemic semi-dark region of rats in different groups at different time points.Results:1.Rat neurological deficit scores of each groupAt 12 h and 1d after ischemia-reperfusion,the scores of model group and EP group were higher,and there was no significant difference between model group and EP group(P>0.05);at 3d and 7d after ischemia-reperfusion,the score of model group was higher than that of EP group,which was significant(P<0.05).2.The expression of Cx43 protein in the semi-dark zone of cerebral ischemia in each group3d and 7d after ischemia-reperfusion,the expression of Cx43 protein in the EP group was higher than that in the sham group,which was significant(P<0.05).The expression of Cx43 protein in the EP group was lower than that of the model group,which was significant(P<0.05).3.The expression of p-Cx43 protein in semi-dark zone of cerebral ischemia in each group3 days after ischemia-reperfusion,the expression of p-Cx43 protein in the EP group was lower than that in the sham group,which was significant(P<0.05).The expression of p-Cx43 protein in the EP group was higher than that of the model group,which was significant(P<0.05);7d,the expression of p-Cx43 protein in the EP group was higher than that in the model group,which was significant(P<0.05).4.The expression of GFAP protein in semi-dark zone of cerebral ischemia in each groupWestern blot showed that 3d and 7d after ischemia-reperfusion,the expression of GFAP protein in the EP group was higher than that in the sham group,which was significant(P<0.05).The expression of GFAP protein in the EP group was lower than that in the model group.Compared with model group and EPS group,it was significant(P<0.05).Immunofluorescence showed that3 days after ischemia-reperfusion,the average optical density value of GFAP fluorescence expression in EP group was higher than that in sham group,which was significant(P<0.05).The average optical density value of GFAP fluorescence expression in EP group was lower than that of the model group,which was significant(P<0.05);on the 7th day,the average optical density value of GFAP fluorescence expression in the EP group was lower than that of the model group,which was significant(P<0.05).Experiment 2 Exercise preconditioning in the ischemic penumbra of rats after cerebral ischemia-reperfusion influence of gap connection communicationMethod:120 rats were randomly divided into 5 groups,namely sham group,model group,EPS group,EP group,CBX group,24 rats in each group,and then divided into four time points after reperfusion 12 h,1d,3d,7d 4subgroups(n=6).The sham group and the model group were not given any treatment.The EPS group and the EP group were given 3 weeks of exercise preconditioning before modeling.The EPS group was modeled with the sham group,the EP group was modeled with the model group,and the CBX group was not treated with any treatment,CBX is injected before modeling,then the model was the same as the model group.After successful modeling,at 12 h,1d,3d,7d,at four time points,m NSS was used to evaluate the neurological deficit of each group of rats;Western blots were used to detect PKC,MAPK,PTK,and calcium levels in the ischemic penumbra protein expression.Results:1.Rat neurological deficit scores of each groupAt 12 h,1d,3d,and 7d after ischemia-reperfusion,the scores were higher than those of the EP group and CBX group.With the prolongation of cerebral ischemia time,the model group,EP group,and CBX scores all decreased.At3 d after reperfusion,the model group was higher than the EP group and the CBX group,and the difference was significant(P < 0.05);7d,the EP group was lower than the model group and the CBX group,the difference was significant(P < 0.05),The model group is higher than the CBX group,and the difference is significant(P<0.05).2.The expression of PKC protein in semi-dark zone of cerebral ischemia in each group3 days after ischemia-reperfusion,the expression of PKC protein in the EP group was higher than that in the model group,sham group,EPS group,and CBX group,which was significant(P<0.05).On the 7th day,the expression of PKC protein in the EP group was higher than that in the model group,sham group,and CBX group,which was significant(P<0.05).3.The expression of MAPK protein in cerebral ischemic penumbra of rats in each group3 days and 7 days after ischemia-reperfusion,the expression of MAPK protein in the EP group was higher than that in the model group,sham group,EPS group,and CBX group,which was significant(P<0.05).4.The expression of PTK protein in semi-dark zone of cerebral ischemia in each group3 days and 7 days after ischemia-reperfusion,the expression of PTK protein in the EP group was higher than that in the model group,sham group,EPS group,and CBX group,which was significant(P<0.05).5.The expression of calmodulin in the ischemic penumbra of rats in each group3 days and 7 days after ischemia-reperfusion,the calmodulin expression in the EP group was higher than that in the sham group and the EPS group,which was significant(P<0.05).The calmodulin expression in the EP group was lower than that in the model group,which was significant(P<0.05).Conclusion:1.Exercise preconditioning can improve the neurological deficit in rats after cerebral ischemia-reperfusion.2.Exercise preconditioning promotes p-Cx43 protein expression,inhibits Cx43 protein expression,and reduces GFAP protein expression after cerebral ischemia-reperfusion in rats.3.Exercise preconditioning regulates the expression of Cx43 protein and GFAP protein,promotes the expression of PKC,MAPK,PTK and regulates calmodulin protein,which may be the protective mechanism of exercise preconditioning for brain injury. |
PDF Full Text Request