Figure 4. BPA-MS is membrane-impermeant as shown by results in C-A patches. (A) Contains current traces from a representative cell expressing BK α + β1 subunits. Currents were recorded in C-A mode in symmetrical K+ (pCa 7) at a patch potential of +40 mV. BPA-MS had no effect on NPo, but BPA increased NPo. (B) Shows group data (n = 8) illustrating the effect of BPA, but not BPA-MS, to increase NPo in C-A patches of BK α + β1. Asterisk indicates P < 0.05 by 1RM-ANOVA with Bonferroni post test. (C) Indicates that similar results were obtained using a 10-fold higher concentration of BPA and BPA-MS (n = 5).