Positive Feedback Mechanisms among Local Ca Releases, NCX, and I_CaL Ignite Pacemaker Action Potentials.

ABSTRACT: Recent data suggest that cardiac pacemaker cell function is determined by numerous time-, voltage-, and Ca-dependent interactions of cell membrane electrogenic proteins (M-clock) and intracellular Ca cycling proteins (Ca-clock), forming a coupled-clock system. Many aspects of the coupled-clock system, however, remain underexplored. The key players of the system are Ca release channels (ryanodine receptors), generating local Ca releases (LCRs) from sarcoplasmic reticulum, electrogenic Na/Ca exchanger (NCX) current, and L-type Ca current (I_CaL). We combined numerical model simulations with experimental simultaneous recordings of action potentials (APs) and Ca to gain further insight into the complex interactions within the system. Our simulations revealed a positive feedback mecha

SUBMITTER: Lyashkov AE 

PROVIDER: S-EPMC5883559 | biostudies-literature | 2018 Mar

REPOSITORIES: biostudies-literature