Ce SLO-1 and hum KCNMA1 currents are blocked by the BK channel antagonist penitrem A.

<p><b>A</b>. Representative whole cell currents recorded from HEK293 cells expressing either Ce SLO-1 or hum KCNMA1 before and after penitrem A (1μM) application. Membrane potential was held at -60mV and stepped to between -100 and +90mV in 10mV increments for 50ms. <b>B</b>. A time-course of steady state Ce SLO-1 and hum KCNMA1 currents at +70mV (stepped every 10s for 40ms from -60mV holding potential) before and during application of DMSO (0.01%) or penitrem A (1μM). The current response is shown as a percentage change from the mean of pre-drug current amplitude during the 0 to 2 min time period. An arrow indicates the time point at which the drug solution reached the chamber with the cells. Free intracellular [Ca²⁺] was 100μM for Ce SLO-1 and 300nM for hum KCNMA1. Data points are the mean ± s.e.mean. p<0.0001 for penitrem A inhibited current compared to DMSO treatment, two-way ANOVA with Bonferroni post-hoc tests.