中文摘要：

目的探讨脑动脉细胞间缝隙连接在高血压病中的变化。方法应用全细胞膜片钳、定量RT-PCR和Western blot技术,比较自发性高血压（SH）大鼠（n=30）和Wistar大鼠（n=30）脑动脉上缝隙连接耦联力,以及连接蛋白45（Cx45）在mRNA和蛋白水平的表达。结果①应用全细胞膜片钳技术发现,SH大鼠脑动脉平滑肌细胞膜电容和膜电导都明显高于正常Wistar大鼠（P〈0.05）,提示SH大鼠脑动脉平滑肌细胞间的缝隙连接耦联力增强。②应用定量RT-PCR技术发现,SH大鼠脑动脉Cx45 mRNA的表达升高（P〈0.05）。③应用Western blot发现,SH大鼠脑动脉Cx45的蛋白表达升高（P〈0.01）。结论 SH大鼠可能通过上调平滑肌细胞上Cx45的表达,增强脑动脉平滑肌细胞间缝隙连接通讯,保证血管的同步收缩。

英文摘要：

Objective To investigate the change of gap junction in brain artery of spontaneous hypertension（SH） rats and its relationship with hypertension.Methods Whole-cell patch-clamp,quantitative RT-PCR and Western blot technique were used to investigate the difference in electrophysiological properties of gap junction and expressions of connexin 45（Cx45） at mRNA and protein levels in brain artery between SH rats（n=30） and Wistar rats（n=30）.Results ① As detected by whole-cell patch-clamp technique,the membrane capacitance and membrane conductance of vascular smooth muscle cells in brain artery from SH rats were significantly higher than that from normotensive Wistar rats（P0.05）,suggesting that gap junctions coupling among VSMCs were enhanced in SH rats.② As detected by quantitative RT-PCR technology,the level of Cx45 mRNA expression in brain artery from SH rats was significantly increased compared with that from normotensive Wistar rats（P0.05）.③ As detected by Werstern blot technique,the expression of Cx45 protein was significantly elevated in brain artery from SH rats compared with that from normotensive Wistar rats（P0.01）.Conclusion The upregulation of Cx45 expression can enhance gap junctional communication in vascular smooth muscle cells of brain artery from SH rats to ensure the synchronous contraction of brain artery.