Sarcolemmal K_ATP channels in the heart: Molecular mechanisms brought to light, but physiologic consequences still in the dark

ATP-sensitive potassium (K_ATP) channels are inhibited by intracellular ATP and thus couple the metabolic state of the cell to its electrical activity. Tremendous progress has been made in the identification of the molecular basis of K_ATP channel function and regulation. The answer to one key question, however, has proven elusive: What are the precise conditions for, and functional consequences of, sarcolemmal K_ATP activation in physiologic and pathophysiologic states? Here we consider recent studies of the molecular basis of cardiac K_ATP channel activity and the role of these channels in cardiac function during ischemia.