实验性蛛网膜下腔出血后脑血管痉挛兔基底动脉Cx43蛋白表达的时相变化

Altered expression of connexin43 in rabbit basilar artery during cerebral vasospasm due to experimental subarachnoid hemorrhage

目的通过建立兔二次蛛网膜下腔出血实验模型,观察兔蛛网膜下腔出血后基底动脉缝隙连接蛋白Cx43表达的时相变化特点,初步探讨蛛网膜下腔出血后脑血管痉挛的形成机制。方法选择健康新西兰大白兔30只,随机分为5组:正常对照组(n=6)和蛛网膜下腔出血模型组(1d、3d、7d和14d,n=6);建立兔二次蛛网膜下腔出血后脑血管痉挛实验模型,脑血管造影分析基底动脉的直径变化并应用Western Blot检测基底动脉Cx43蛋白的表达变化。对血管直径与Cx43表达变化情况进行相关分析。结果成功建立兔二次蛛网膜下腔出血模型;脑血管造影显示注血后1d基底动脉即出现痉挛(85.7%±8.6%,P<0.05);7d时达高峰(66.5%±7.6%,P<0.01);14d时仍有痉挛(78.4%±8.2%,P<0.05)但程度较前缓解。Cx43蛋白表达在建立SAH模型后1d(38.6%±5.6%,P<0.05)、3d(50.2%±5.7%,P<0.05)、7d(57.8%±5.3%,P<0.01)、14d(32.4%±3.6%,P<0 0.05)均升高,其中7d为高峰,14d开始下降。Cx43蛋白表达的时相性变化与SAH后基底动脉直径的时相性变化相关系数为0.914。结论实验结果显示蛛网膜下腔出血后兔基底动脉缝隙连接蛋白Cx43的表达发生了时相性变化,并且Cx43蛋白表达强弱与蛛网膜下腔出血后脑血管痉挛程度在时程上存在正相关关系,表明缝隙连接蛋白Cx43可能参与蛛网膜下腔出血后脑血管痉挛的形成。

Objective The study was designed to explore the change of expression of connexin43（Cx43） protien in the model of subarachnoid hemorrhage（SAH） of rabbits,hoping to provide the basis to study the mechanism of cerebral vasospasm（CVS）.Methods 30 New Zealand rabbits were divided into 5 groups：SAH group（1d,3d,7d,14d,n=6） and control group（n=6）.The model of CVS following SAH was established.Digital subtraction angiography was performed to detect the change of the basilar arteries diameter.The expression of Cx43 protien in basilar arteries tissue at different time points following experimental SAH was examined by using western blotting analysis.The data were statistically analyzed using the bivariate correlations test.Results The model of SAH in rabbits was successfully established.All 30 rabbits were analyzed.Cerebral angiograms on 1d,3d,7d and 14d showed severe narrowing of the BAs,and on 7d showed the most narrowing and on 14d began to Relieve.Western blotting showed that the expression of Cx43 protein were detected in normal rabbit basilar arteries tissue.However,the expression of Cx43 protein increased gradually and significantly in models compared with that of control（P〈0.05）,which reached peak on 7d（P〈0.01） and then decreased on 14d（P〈0.05）.There was positive correlation between expression of Cx43 and cerebral vasospasm.Conclusions The above results demonstrates at the first time that the Cx43 protein expression is altered after the SAH,and exhibits a time-dependent change.which might be connected with the development of CVS.In summary,our data demonstrates gap junctions may play an important role in the pathogenesis of cerebral vasospasm after SAH.