ATP-sensitive and large-conductance calcium-activated potassium channels (KATP and BKCa)

The ATP-sensitive potassium (KATP) and large-conductance calcium-activated potassium (BKCa) channels are distinct classes of ion channels that integrate metabolic and ionic signals to regulate cellular excitability and vascular tone [1, 11]. KATP channels are hetero-octameric complexes consisting of inwardly rectifying potassium subunits (Kir6.x) and regulatory sulfonylurea receptors (SUR), which sense the intracellular ATP/ADP ratio to couple metabolism with membrane potential [1, 6]. BKCa channels, also known as Maxi-K or KCa1.1, are activated by both membrane depolarization and elevated intracellular calcium, acting as a critical negative feedback mechanism to limit calcium entry and promote smooth muscle relaxation [11, 16]. Both channels are significant in the pathophysiology of migraine, where their activation by vasodilators like CGRP and nitric oxide contributes to the induction of headache attacks [3, 10]. While KATP channels are established targets for diabetes (sulfonylureas) and hypertension (minoxidil), both channel types are currently being explored for their roles in neuroprotection, cardioprotection, and as novel therapeutic targets for migraine prevention [12, 17]. Due to their ubiquitous expression, drugs targeting these channels must be carefully designed to avoid systemic side effects such as hypoglycemia or cardiovascular instability [7, 18].

Other names

KATPBKCaMaxi-KBK channelKCa1.1Kir6SURSlo1Big-conductance calcium-activated potassium channel

These channels modulate potassium efflux to regulate membrane potential; KATP channels link cellular metabolism to excitability via ATP/ADP sensing, while BKCa channels provide negative feedback to calcium-induced depolarization [1, 11, 16].