Haefliger J A, Castillo E, Waeber G, Bergonzelli G E, Aubert J F, Sutter E, Nicod P, Waeber B, Meda P
Department of Internal Medicine B, University Hospital, CHUV-1011 Lausanne, Switzerland.
Circulation. 1997 Feb 18;95(4):1007-14. doi: 10.1161/01.cir.95.4.1007.
Connexin43 (Cx43), a membrane protein involved in the control of cell-to-cell communication, is thought to play a role in the contractility of the vascular wall and in the electrical coupling of cardiac myocytes. The aim of this study was to investigate the effects of experimental hypertension on Cx43 expression in rat aorta and heart.
Rats were made hypertensive after one renal artery was clipped (two kidney, one-clip renal model) or after the administration of deoxycorticosterone and salt (DOCA-salt model). After 4 weeks, all rats showed a similar increase in intra-arterial mean blood pressure and in the thickness of both the aortic wall and the heart. Northern blot analysis of aorta mRNA and immunolabeling for Cx43 showed that hypertensive rats expressed twice as much Cx43 in aorta as the control animals. In contrast, no difference in Cx43 mRNA or in the immunolabeled protein was observed in heart.
The results show that rats exhibiting a similar degree of blood pressure elevation, as the result of different mechanisms, feature a comparable increase in Cx43 gene expression, which was observed in the aortic but not in the cardiac muscle. These data suggest that localized mechanical forces induced by hypertension are major tissue-specific regulators of Cx43 expression.
连接蛋白43（Cx43）是一种参与细胞间通讯控制的膜蛋白，被认为在血管壁的收缩性和心肌细胞的电偶联中发挥作用。本研究的目的是探讨实验性高血压对大鼠主动脉和心脏中Cx43表达的影响。
通过夹闭一侧肾动脉（双肾一夹肾模型）或给予脱氧皮质酮和盐（DOCA-盐模型）使大鼠患高血压。4周后，所有大鼠的动脉平均血压以及主动脉壁和心脏的厚度均出现相似程度的增加。对主动脉mRNA进行Northern印迹分析以及对Cx43进行免疫标记显示，高血压大鼠主动脉中Cx43的表达量是对照动物的两倍。相比之下，在心脏中未观察到Cx43 mRNA或免疫标记蛋白有差异。
结果表明，由于不同机制导致血压升高程度相似的大鼠，其Cx43基因表达有相当程度的增加，这在主动脉中观察到，但在心肌中未观察到。这些数据表明，高血压诱导的局部机械力是Cx43表达的主要组织特异性调节因子。
