ATP-sensitive potassium channel (vascular type) (KATP channel)

ATP-sensitive potassium channels (vascular type) are hetero-octameric complexes formed by inward-rectifier potassium channel subunits (primarily Kir6.1 encoded by KCNJ8) and regulatory sulfonylurea receptor subunits (type SUR2B, encoded by ABCC9), localized predominantly within vascular smooth muscle[1][4]. These channels link cellular metabolic state—reflected by the ATP/ADP ratio—to the cell’s membrane potential: they are inhibited by intracellular ATP and activated by ADP, leading to hyperpolarization of the smooth muscle membrane when open, which decreases Ca2+ influx and induces vasodilation[4][1][5]. Vascular KATP channels play key roles in blood pressure regulation and protection against ischemic injury[1], and are important drug targets for antihypertensive vasodilators (e.g., minoxidil, diazoxide) as well as side-effect targets for sulfonylurea antidiabetic drugs[4][1].

Other names

Vascular KATP channelVascular ATP-sensitive K+ channelKir6.1/SUR2B channelPotassium inwardly-rectifying channel subunit Kir6.1-Sulfonylurea receptor 2B complex

Channel blockers inhibit KATP channel activity, increasing membrane excitability, and can constrict vessels. Channel openers activate KATP channels, leading to membrane hyperpolarization, reducing Ca2+ influx, and causing vasodilation[4][1].