Figure 16. Store operated Ca²⁺ entry (SOCE) in USM.

A, relative expression of TRPC genes in FACS sorted and unsorted urethral cells from SMC‐eGFP mice determined by qPCR analysis, normalized to Gapdh expression (n = 4). B, relative expression of Orai channel genes in FACS sorted and unsorted urethral cells from SMC‐eGFP mice determined by qPCR analysis, normalized to Gapdh expression (n = 4). C, representative contractile data showing a protocol to induce SOCE in USM. Basal USM contraction is shown at the start of the trace when intracellular Ca²⁺ stores were passively depleted by incubating the tissue in 0 mm Ca²⁺ solution and thapsigargin (10 μm). Reintroduction of [Ca²⁺]_o (2.5 mm) in the continued presence of thapsigargin led to development of a sustained tonic contraction that was insensitive to nifedipine. D, contractile trace showing the effect of GSK 7975A (1–10 μm) on SOCE induced tonic contraction of USM. E, summary data showing the effects of nifedipine and GSK 7975A on the sustained tonic contraction induced in USM using the SOCE protocol described in C and D. Contractions are expressed as fold changes normalized to contractile level in 0 mm Ca²⁺ + thapsigargin (10 μm; n = 8). ns, not significant, ^* p < 0.05, ^** p < 0.01.