Figure 5. Phenylephrine increases USMC Ca²⁺ transient firing.

A, relative expression of adrenergic α1 receptor genes in FACS sorted and unsorted urethral cells from SMC‐eGFP mice determined by qPCR analysis, normalized to Gapdh expression (n = 4). Ba and b, representative ST maps of Ca²⁺ transient firing within a single USMC recorded in situ during control conditions (a) and after incubation with 10 μm phenylephrine (b). C, 3‐D plots of the ST maps shown in A. Da–d, summary data showing the effect of 10 μm phenylephrine on USMC Ca²⁺ transient frequency (a), amplitude (b), duration (c) and spatial spread (d) (c = 34, n = 10). ns, not significant, ^** p < 0.01, ^*** p < 0.001, ^**** p < 0.0001.