Ryanodine-induced vasoconstriction of the gerbil spiral modiolar artery depends on the Ca2+ sensitivity but not on Ca2+ sparks or BK channels

摘要

BackgroundIn many vascular smooth muscle cells (SMCs), ryanodine receptor-mediated Ca²⁺ sparks activate large-conductance Ca²⁺-activated K⁺ (BK) channels leading to lowered SMC [Ca²⁺]i and vasodilation. Here we investigated whether Ca²⁺ sparks regulate SMC global [Ca²⁺]i and diameter in the spiral modiolar artery (SMA) by activating BK channels.