Cx43和Cx45在自发性高血压和正常血压大鼠主动脉的表达差异

Differenceexpression of Cx43 and Cx45 in aorta of spontaneously hypertensive rats and normotensive rats

目的探讨连接蛋白(Cx)在自发性高血压大鼠(SHR)和正常血压大鼠主动脉表达的异同。方法应用定量RT-PCR、Werstern blot和透射电镜技术比较SHR和正常血压大鼠主动脉上Cx43和Cx45的mRNA和蛋白表达水平以及平滑肌细胞间缝隙连接的形态学改变。结果 1RT-PCR结果显示SHR主动脉Cx45 mRNA的表达降低(P<0.05),Cx43 mRNA的表达降低更为显著(P<0.01);2RT-PCR结果显示SHR主动脉Cx43和Cx45蛋白的表达显著降低(P<0.01),Cx43磷酸化水平没有变化;3电镜显示主动脉平滑肌细胞间缝隙连接的数量显著减少。结论高血压可能通过降低主动脉平滑肌细胞上Cx43和Cx45的表达造成细胞间缝隙连接的通讯功能降低,导致血管功能紊乱,进一步加重高血压造成的伤害。

【Objective】To investigate the expression of connexins in aorta of the spontaneously hypertensive rats（SHR） and normotensive rats.【Methods】The difference of connexin 43（Cx43） and Cx45 mRNA and protein expression between SHR and normotensive rats aorta were detectedby quantitative RT-PCR and Western-blot respectively,and the morphological change of gap junctionbetween smooth muscle cellswas examined by transmission electron microscopy. 【Results】1The aortic Cx45 mRNA of SHR was decreased compared with the normotensive rats（P〈0.05）, but more significantly in Cx43（P〈0.01）. 2The aortic Cx43 and Cx45 protein of SHR were significantly decreased compared with the normotensive rats（P〈0.01）, but the level of phosphorylated Cx43 was not changed in aorta（P〉0.05）. 3The number of gap junctions between smooth muscle cells was significantly lower in SHR than in normotensive rats. 【Conclusion】Hypertension could down-regulate the expression of Cx43 and Cx45 and decrease the number of gap junction between aortic smooth muscle cells to make vascular function disorders, further aggravating the damage induced by hypertension.