Pulmonary Circulation Under Pressure: Pathophysiological and Therapeutic Implications of BK Channel.

The large-conductance Ca-activated K (BK) channel is widely expressed in the pulmonary blood vessels and plays a significant role in regulating pulmonary vascular tonus. It opens under membrane depolarization, increased intracellular Ca concentration, and chronic hypoxia, resulting in massive K efflux, membrane hyperpolarization, decreased L-type Ca channel opening, and smooth muscle relaxation. Several reports have demonstrated an association between BK channel dysfunction and pulmonary hypertension (PH) development.