L-type voltage-dependent calcium channel (often specified further as subunits such as CaV1.2 in humans) (VDCC)

The principal calcium channels in bronchial (airway) smooth muscle are L-type voltage-dependent calcium channels (especially CaV1.2) and, to a lesser degree, T-type channels. These channels mediate calcium entry following membrane depolarization, which is a crucial trigger for smooth muscle contraction. Activation is typically downstream of contractile agonists (e.g., acetylcholine, histamine, and leukotrienes) that act through G protein-coupled muscarinic or other receptors, leading to membrane depolarization and opening of the channels. L-type calcium channels also help refill sarcoplasmic reticulum calcium stores after contraction. Calcium channel blockers are used therapeutically to reduce airway constriction by inhibiting these channels, producing bronchodilation, and are of particular relevance in asthma management. Other channels, such as the calcium-activated chloride channel TMEM16A, modulate both smooth muscle contraction and mucus secretion, representing an emerging therapeutic target. The term "Bronchial smooth muscle calcium channel" is an umbrella and should be refined to the molecular level for therapeutic or research purposes; "L-type voltage-dependent calcium channel (CaV1.2)" is the recommended canonical form for most airway smooth muscle-specific studies and interventions.

Other names

Airway smooth muscle calcium channelASM calcium channelCaV1.2

Blockade of L-type calcium channels reduces calcium influx, inhibits smooth muscle contraction, and elicits bronchodilation (bronchodilator effect). Blockade of T-type channels (less prominent in bronchial smooth muscle) may contribute to vasodilatory and renoprotective actions. Blockade of calcium-activated chloride channels (TMEM16A) indirectly modulates smooth muscle contraction and mucus secretion.