Inward rectifiers in the heart: An update on I-K1

The cardiac inward rectifier potassium current (I-K1), present in all ventr icular and atrial myocytes, has been suggested to play a major role in repo larization of the action potential and stabilization of the resting potenti al. The molecular basis is now ascribed to members of the Kir2 sub-family o f inward rectifier K channel genes, and the availability of recombinant exp ression systems has led to elucidation of the mechanism of inward rectifica tion. as well as additional regulatory mechanisms involving intracellular p H and phosphorylation. In vivo manipulation of the genes encoding I-K1 and regulatory proteins now promise to provide Hew Insights to the role of this conductance in the heart. This review details recent advances and consider s the prospects for further elucidation of the role of this conductance in cardiac electrical activity. (C) 2001 Academic Press.