Vascular potassium channel (K+ channel)

Vascular potassium channels are a heterogeneous group of ion channels located in the plasma membrane of vascular smooth muscle and endothelial cells, where they serve as primary regulators of vascular resistance and blood flow (Jackson, 2018, Microcirculation). The major classes include voltage-gated (Kv), calcium-activated (KCa), ATP-sensitive (KATP), and inward-rectifier (Kir) potassium channels (Nelson & Quayle, 1995, Am J Physiol). By facilitating the efflux of potassium ions, these channels maintain the resting membrane potential; their opening causes hyperpolarization, which prevents the activation of voltage-gated calcium channels and leads to smooth muscle relaxation (Tykocki et al., 2017, Comprehensive Physiology). Impairment of K+ channel function is a hallmark of several vascular diseases, including hypertension and coronary artery disease. Therapeutic agents known as potassium channel openers, such as minoxidil and nicorandil, are used clinically to induce vasodilation in conditions like resistant hypertension and angina (PubChem, 2024). Despite their efficacy, systemic use can be limited by side effects like reflex tachycardia and fluid retention.

Other names

Vascular K+ channelArterial potassium channelVascular smooth muscle potassium channel

Activation of vascular K+ channels promotes potassium efflux, leading to membrane hyperpolarization of vascular smooth muscle cells. This hyperpolarization closes voltage-gated L-type calcium channels, reducing intracellular calcium concentration and causing vasodilation (Nelson & Quayle, 1995, Am J Physiol).