Veeraraghavan Rengasayee, Poelzing Steven, Gourdie Robert G
Center for Cardiovascular and Regenerative Biology, Virginia Tech Carilion Research Institute , Roanoke, VA , USA.
Cell Commun Adhes. 2014 Jun;21(3):161-7. doi: 10.3109/15419061.2014.905932. Epub 2014 Apr 15.
Cardiac conduction is the propagation of electrical excitation through the heart and is responsible for triggering individual myocytes to contract in synchrony. Canonically, this process has been thought to occur electrotonically, by means of direct flow of ions from cell to cell. The intercalated disk (ID), the site of contact between adjacent myocytes, has been viewed as a structure composed of mechanical junctions that stabilize the apposition of cell membranes and gap junctions which constitute low resistance pathways between cells. However, emerging evidence suggests a more active role for structures within the ID in mediating intercellular electrical communication by means of non-canonical ephaptic mechanisms. This review will discuss the role of the ID in the context of the canonical, electrotonic view of conduction and highlight new, emerging possibilities of its playing a more active role in ephaptic coupling between cardiac myocytes.
心脏传导是电兴奋在心脏中的传播，负责触发单个心肌细胞同步收缩。传统上，这个过程被认为是通过离子在细胞间的直接流动以电紧张方式发生的。闰盘（ID）是相邻心肌细胞之间的接触部位，被视为由机械连接和缝隙连接组成的结构，机械连接可稳定细胞膜的并列，缝隙连接构成细胞间的低电阻通路。然而，新出现的证据表明，ID内的结构通过非经典的电突触机制在介导细胞间电通信中发挥更积极的作用。本综述将在传统的、电紧张性传导观点的背景下讨论ID的作用，并强调其在心肌细胞间电突触耦合中发挥更积极作用的新的、正在出现的可能性。
