ATP-sensitive potassium channel (K-ATP channel) (K-ATP channel)

The ATP-sensitive potassium (K-ATP) channel is a hetero-octameric protein complex that functions as a metabolic sensor, coupling the intracellular ATP/ADP ratio to the cell's membrane potential (UniProt, 2024). It is composed of four pore-forming subunits, typically Kir6.1 (KCNJ8) or Kir6.2 (KCNJ11), and four regulatory sulfonylurea receptor subunits, such as SUR2B (ABCC9) in vascular smooth muscle and hair follicles (PubMed, 14996101). In vascular tissues, the opening of these channels causes potassium efflux and membrane hyperpolarization, which inhibits voltage-gated calcium channels, leading to vasodilation and decreased peripheral resistance (StatPearls, 2023). In the hair follicle, K-ATP channel openers like minoxidil are believed to stimulate the dermal papilla cells and promote the transition of hair follicles from the telogen to the anagen phase, thereby increasing hair growth and density (PubMed, 14996101). These channels are primary targets for antihypertensive agents and treatments for androgenetic alopecia. However, systemic activation can lead to side effects such as hypotension, reflex tachycardia, and unwanted hair growth (hypertrichosis) (StatPearls, 2023).

Other names

ATP-dependent potassium channelKir6/SUR complexK-ATP channelInwardly rectifying potassium channelATP-sensitive potassium channel in hair follicles and vascular smooth muscle

Potassium channel opening leading to membrane hyperpolarization and reduced calcium influx