Fig. 6.

Roles of K_v7 voltage-dependent K⁺ (K_v7) channels in maintaining the synchrony of spontaneous Ca²⁺ transients.

In three mural cells of rat rectal precapillary arteriole (PCA), XE 991 (10 μM), a blocker of K_v7 channels, converts synchronous spontaneous Ca²⁺ transients into asynchronous, high-frequency Ca²⁺ transients and increases the basal Ca²⁺ level (A). Subsequent nifedipine decreases their frequency but does not restore the synchrony. In an XE991-treated rectal PCA where asynchronous spontaneous Ca²⁺ transients are generated, levcromakalim, an ATP-sensitive K⁺ channel opener that is known to hyperpolarise mural cells, restores their intercellular synchrony (B). Traces are reproduced from (49) with permission.