Fig. 1.

Pharmacological blockade of phosphodiesterase (PDE) with 10 μM 3-isobutyl-1-methylxanthine (IBMX) increased the spontaneous transient outward currents (STOCs) frequency in human urinary bladder smooth muscle (UBSM)-isolated cells. A: original recording illustrating that PDE blockade increased the frequency of STOCs in a single UBSM cell. Portions of the recording are shown on an expanded time scale before and after IBMX application. B: summary data showing that PDE blockade significantly increased the STOCs frequency without a significant effect on the STOCs amplitude [n = 4, N = 4; *P < 0.05; nonsignificant (NS)]. The STOCs frequency and average amplitude under control conditions were taken to be 100%, respectively.