Ionic Current and Pacemaker Activity of the S-A Node Cells : Symposium on Sinus Node Function and Its Abnormality

Publisher Website
Google Scholar
Abstract
Five membrane currents were observed in rabbit S-A [sinoatrial] node cells by the voltage clamp method. The outward current (ik) was carried by ion, while the inward current (is) was mainly carried by Na ion with some contribution of Ca ion. The inward current activated by hyperpolarization (ih) was a mixed current system, but participation of Na and Cl ions existed. Each current was analyzed according to the Hodgkin-Huxley type equation. The action potential and pacemaker activity of S-A node were reconstructed. In phase 4 diastolic depolarization, is played the major role, but the assistance of ik was also important.