Effects Of Exercise Preconditioning On Blood-brain Barrier Permeability And Cx43 And Pannexin1 Protein Expression In Rats After Cerebral Ischemia-reperfusion Injury

Objective:To investigate the effect of exercise preconditioning on the permeability of blood brain barrier and the expression of CX43 and Pannexinl protein after cerebral ischemia-reperfusion injury in rats,and to elucidate its Neuroprotective mechanism.Methods:The 36 SPF male SD rats were randomly divided into three groups:sham group,model group and exercise preconditioning group.12 rats in each group.The middle cerebral artery occlusion and ischemia-reperfusion model was made in the model group and exercise preconditioning group by modified Koizumi suture method.The exercise preconditioning group was trained for three weeks before making the model.The neural function was evaluated by modified Neurological Severity Scores at 24 h after ischemia and reperfusion,and then the permeability of BBB was quantitatively analyzed by EB osmotic method.The expression of Cx43 and Pannexinl protein in ischemic brain tissue were detected by Western Blotting.Results:1.Modified Neurological Severity Scores:The rats in sham group had no neurological deficit after 24h of cerebral ischemia-reperfusion.The neurological function score in the model group was significantly higher than that in the sham group(P<0.05).Compared with the model group,the score of the exercise preconditioning group was significantly lower,the difference was statistically significant(P<0.05).2.Blood-brain barrier permeability:the results showed that after 24 h of cerebral ischemia-reperfusion,EB content in model group was significantly higher than that in sham group(P<0.05).Compared with model group,EB content in exercise preconditioning group decreased significantly,the difference was statistically significant(P<0.05).3.Changes of Cx43 and Pannexinl proteins in ischemic penumbra:24 hours after cerebral ischemia-reperfusion,the expression of Cx43 protein and Pannexinl protein in model group was significantly higher than that in sham operation group(P<0.05),Compared with the model group,the expression of Cx43 protein and Pannexinl protein in the exercise preconditioning group decreased significantly,the difference was statistically significant(P<0.05).Conclusion:1.Exercise preconditioning can improve the nerve function defect after cerebral ischemia-reperfusion injury in rats and play a protective role in the brain.2.Exercise preconditioning improves blood brain barrier permeability after cerebral ischemia reperfusion on rats,down-regulates expression of Cx43 and Pannexinl protein.