Effect of BK opener on PBOO-induced spontaneous contraction and myosin light chain 20 (MLC20) phosphorylation. A: set of representative recordings of detrusor muscle strips after addition of BK opener NS1619 or isoparamic acid. Top tracing is no treatment as a control, middle tracing is after treatment with NS1619, and bottom tracing is after treatment with isoparamic acid. B: set of representative 2-dimensional gels for control and BK opener-treated muscle strips. Top gel is no treatment, middle tracing is after treatment with NS1619, and bottom tracing is after treatment with isoparamic acid. UP-MLC20, unphosphorylated MLC20; P-MLC20, phosphorylated MLC20.