Figure 5. When BK channels contain β1 subunits, BPA-MS can activate from the cytoplasmic face of the membrane. (A) Shows a family current traces at +40 mV in a representative I-O patch with BK α (symmetrical 140 mM K+; pCa 6.3). The shaded inset shows a portion of the same current traces on an expanded time scale. (B) Contains group data (n = 8) and shows that 100 μM BPA-MS does not significantly increase the NPo of BK α. In contrast, 100 μM BPA significantly increases NPo. Asterisk indicates P < 0.05 vs. control by 1RM-ANOVA with Bonferroni post test. (C) Shows a family of current traces at +40 mV from a representative I-O patch of BK α + β1 (symmetrical 140 mM K+; pCa 7). The shaded inset shows a portion of the same traces on an expanded time scale. (D) Contains group data (n = 15) showing a significant increase in NPo elicited by BPA-MS and BPA. Asterisk indicates P < 0.05 vs. control by 1RM-ANOVA with Bonferroni post test. Dagger indicates P < 0.05 vs. control and BPA-MS by 1RM-ANOVA with Bonferroni post test.