Vascular potassium channels (K channels)

Vascular potassium channels are a diverse group of membrane proteins located in the smooth muscle and endothelial cells of blood vessels, playing a critical role in regulating vascular tone and blood pressure (Silva-Filho et al., 2012). These channels, which include large-conductance calcium-activated potassium (BKCa) channels and ATP-sensitive potassium (KATP) channels, are primary targets for various vasodilatory agents (Wang et al., 2014). Borneol, a bicyclic monoterpene found in many medicinal plants, has been identified as a modulator of these channels, promoting their opening (Journal of Ethnopharmacology, 2014). This activation leads to an efflux of potassium ions, causing hyperpolarization of the vascular smooth muscle cell membrane. This hyperpolarization inhibits the entry of calcium through voltage-gated calcium channels, ultimately leading to muscle relaxation and vasodilation (PubChem CID 6433). Consequently, these channels are significant in the context of treating cardiovascular conditions such as hypertension and vasospasm (Life Sciences, 2012).

Other names

Vascular K+ channelsBKCa channelsKATP channelsPotassium-selective channelsLarge-conductance calcium-activated potassium channelsATP-sensitive potassium channels

Borneol acts as an opener of vascular potassium channels, specifically the large-conductance calcium-activated (BKCa) and ATP-sensitive (KATP) subtypes. This activation promotes potassium efflux, leading to membrane hyperpolarization, which subsequently closes voltage-gated calcium channels and reduces intracellular calcium, resulting in vasorelaxation (Wang et al., 2014; Silva-Filho et al., 2012).