Coppen S R, Severs N J, Gourdie R G
National Heart and Lung Institute, Imperial College School of Medicine, Royal Brompton Hospital, London, England.
Dev Genet. 1999;24(1-2):82-90. doi: 10.1002/(SICI)1520-6408(1999)24:1/2<82::AID-DVG9>3.0.CO;2-1.
We previously demonstrated that alpha 6 (Cx45), one of the three connexins of the mammalian myocardium, is preferentially expressed in the peripheral portion of the ventricular conduction system in rats and mice. Here we report that alpha 6 is also prominently immunolocalized in the atrioventricular node and His bundle of these species. The distribution of immunolocalized alpha 6 reveals that the node and bundle form part of an extended central conductive network circumscribing the AV and outflow junctional regions of the fetal, and less continuously, the adult heart. Of the three cardiac connexins, alpha 6 is the isoform most continuously expressed by conduction tissues, and may thus account for the recently reported viability of the alpha 5 (Cx40) knockout mouse. It is concluded that alpha 6 expression is a defining feature of the heterogenous tissues comprising the atrioventricular conduction system of the rodent heart.
我们先前证明，α6（Cx45）是哺乳动物心肌中三种连接蛋白之一，在大鼠和小鼠的心室传导系统外周部分优先表达。在此我们报告，α6在这些物种的房室结和希氏束中也有显著的免疫定位。免疫定位的α6分布显示，该结和束构成了一个延伸的中央传导网络的一部分，该网络围绕胎儿心脏的房室和流出道连接区域，在成体心脏中连续性稍差。在三种心脏连接蛋白中，α6是传导组织最持续表达的异构体，因此可能解释了最近报道的α5（Cx40）基因敲除小鼠的生存能力。得出的结论是，α6表达是构成啮齿动物心脏房室传导系统的异质组织的一个决定性特征。
