OBJECTIVE
Sphingosine-1-phosphate (S-1-P), a potent lysophospholipid mediator which is released from platelets during clotting, activates a G-protein-gated inwardly rectifying K+ current (GIRK) in atrial and sino-atrial node myocytes. We denote this current I(K(S-1-P).) A similar GIRK, which is activated by acetylcholine (ACh) and denoted I(K(ACh)), is expressed in atrium. It shortens the actio...
