Figure 3. The activity of BK_Ca channels in cell-attached patches from normal human oral keratinocytes. Cells were bathed in 145 mM K⁺ solution containing 1.8 mM CaCl₂, and the holding potential was set at +60 mV. (A) Original current tracings obtained in the absence and presence of ionomycin, squamocin, and squamocin plus paxilline. "a" is the control, "b" and "c" were obtained in the presence of either ionomycin (10 µM) or squamocin (10 µM), respectively, and "d" was recorded after application of squamocin (10 µM) plus paxilline (1 µM). (B) Bar graph showing the effects of ionomycin (10 µM), squamocin (10 µM), and squamocin (10 µM) plus paxilline (1 µM) on BK_Ca-channel activity. Mean ± SEM (n = 6–8). *Significantly different from control group. **Significantly different from squamocin-alone group.