Physiological Roles of the Rapidly Activated Delayed Rectifier K⁺ Current in Adult Mouse Heart Primary Pacemaker Activity.

ABSTRACT: Robust, spontaneous pacemaker activity originating in the sinoatrial node (SAN) of the heart is essential for cardiovascular function. Anatomical, electrophysiological, and molecular methods as well as mathematical modeling approaches have quite thoroughly characterized the transmembrane fluxes of Na⁺, K⁺ and Ca²⁺ that produce SAN action potentials (AP) and 'pacemaker depolarizations' in a number of different in vitro adult mammalian heart preparations. Possible ionic mechanisms that are responsible for SAN primary pacemaker activity are described in terms of: (i) a Ca²⁺-regulated mechanism based on a requirement for phasic release of Ca²⁺ from intracellular stores and activation of an inward current-mediated by Na⁺/Ca²

SUBMITTER: Hu W 

PROVIDER: S-EPMC8124469 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature