Initiation of embryonic cardiac pacemaker activity by inositol 1,4,5-trisphosphate-dependent calcium signaling.

ABSTRACT: In the adult, the heart rate is driven by spontaneous and repetitive depolarizations of pacemaker cells to generate a firing of action potentials propagating along the conduction system and spreading into the ventricles. In the early embryo before E9.5, the pacemaker ionic channel responsible for the spontaneous depolarization of cells is not yet functional. Thus the mechanisms that initiate early heart rhythm during cardiogenesis are puzzling. In the absence of a functional pacemaker ionic channel, the oscillatory nature of inositol 1,4,5-trisphosphate (InsP3)-induced intracellular Ca2+ signaling could provide an alternative pacemaking mechanism. To test this hypothesis, we have engineered pacemaker cells from embryonic stem (ES) cells, a model that faithfully recapitulates early stages o

SUBMITTER: Mery A 

PROVIDER: S-EPMC1087245 | biostudies-literature | 2005 May

REPOSITORIES: biostudies-literature