Effect of Adenosine Triphosphate-Sensitive Potassium Channel Inhibitors on Coronary Metabolic Vasodilation

The ATP-sensitive potassium (K_ATP) channel is a distinct type of potassium ion channel that is found in the vascular smooth muscle cells of a variety of mammalian species, including humans. The activity of K_ATP channels is determined by many factors including cellular ATP and ADP levels, thus providing a link between cellular metabolism and vascular tone through its effects on membrane potential. Experimental studies using inhibitors of K_ATP channels, such as the sulfonuylurea class of drugs, indicate that these channels modulate coronary vascular tone including the hyperaemia induced by increased myocardial metabolism. This review examines the evidence linking K_ATP channels to the regulation of coronary vascular tone and the potential clinical implications of pharmacologic therapies that act on K_ATP channels.