Smooth Muscle Cell Membrane Calcium Channel (N/A)

Smooth muscle cell membrane calcium channels are integral membrane proteins that mediate the influx of calcium ions (Ca²⁺) into smooth muscle cells, playing a central role in regulating contraction, gene expression, and cellular signaling. These channels are essential for vascular tone, blood pressure regulation, and various physiological processes in smooth muscle tissues. The primary type is the L-type calcium channel (Cav1.2), which opens in response to depolarization of the cell membrane. Activation allows extracellular Ca²⁺ to enter the cytoplasm, triggering contraction via calmodulin activation and subsequent phosphorylation of myosin light chains by MLCK. Receptor-operated calcium channels open following stimulation by specific ligands binding to G protein-coupled receptors. Store-Operated Calcium Entry (SOCE) is activated when intracellular stores are depleted. Altered function or expression can lead to pathophysiological states such as hypertension or diabetes-related vascular dysfunction.

Other names

Voltage-Dependent Calcium Channels (VGCCs)Receptor-Operated Calcium ChannelsStore-Operated Calcium Entry (SOCE)L-type calcium channel (Cav1.2)

L-type calcium channel blockers reduce vascular smooth muscle contractility by inhibiting Cav1.2-mediated calcium influx.