The Role Of Atorvastatin Pretreatment In Astrocytic Gap Junctional Communication On Focal Cerebral Ischemic Injury

Objective:To study the expressions of CX43 and GFAP following cerebral ischemic injury and pre-administration of atorvastatin in SD rats,and to explore the possible role of gap junctional communication in cerebral ischemic injury with atorvastatin intervention.Methods:Health SD male rats were randomly divided into 3 subgroups(n=42): sham operation group(Sham group,n=14);permanent middle cerebral artery occlusion(MCAO group,n=14);atorvastatin pretreatment group(Ator group,n=14).The MCAO models were established with thread thrombus of middle cerebral artery.Ator group was administrated with atorvastatin(20 mg/kg*d)by gastric gavage for 7 days before the operation.The same volume of physiological salines were given to Sham group and MCAO group,respectively.Modified neurological severity scores(m NSS),which reflects the extent of brain ischemic damage,were evaluated in each group prior to decapitation.All rats were decapitated at 24 hours after operation and subsequently stained with 2% TTC.The cerebral infarction volume was measured by the pathology image analysis system.The immunohistochemical method was used to examine the positive expressions of CX43 and GFAP.The protein expressions of CX43 and GFAP were investigated by Western blotting.Results were analyzed by statistic soft package of SPSS 19.0.Results:1.Neurological severity scores and cerabral infarction volume:As compared with Sham group,the neurological severity scores and cerabral infarction volume in MCAO group were obviously increased.The results of Ator group,however,were lower than MCAO group(P<0.05).2.Immunohistology results:Compared with Sham group,the positive expressions of CX43 and GFAP in MCAO group were distinctly increased(P<0.05).Compared with MCAO group,the expressions of above-mentioned protein were reduced in Ator group(P<0.05).3.Western blotting results:Compared with Sham group,the expressions of CX43 and GFAP protein in MCAO group were increased(P < 0.05).Compared with MCAO group,the expressions of above-mentioned protein were reduced in Ator group(P<0.05).Conclusion:Pretreatment of atorvastatin can decrease neurological severity scores and cerebral infarction volume following cerebral ischemic injury in rats.Atorvastatin-induced down-regulation of CX43 and GFAP can decrease astrocytic gap junctional communication and attenuate astrocytic activation,therefore plays a role in attenuating cerebral ischemic damage.