Figure 2. Regulation of vascular smooth muscle cell (SMC) contractility by voltage-gated Ca2+ channels.
Ca2+ entry through CaV1.2 and CaV3.1 channels promotes SMC contraction. Ca2+ influx through CaV3.2 channels activates ryanodine receptors (RyRs), triggering Ca2+ release from the sarcoplasmic reticulum (SR) in the vicinity of large conductance, Ca2+-activated K+ (BK) channels. BK channel activation results in SMC hyperpolarization and vasodilation. The dotted line indicates the deactivation of CaV1.2 and CaV3.1 channels.