Figure 6

The BK channel blocker penitrem A augments acetylcholine-triggered Ca²⁺influx in KO adrenal gland chromaffin cells to a normal level. WT (A) and KO (B) adrenal gland chromaffin cells from male mice were loaded with Fura2-AM for one hour, and then treated with a BK channel blocker penitrem A (10 μmol/L) for 15 minutes. The cells were then washed and stimulated with acetylcholine at 37 °C. Their Ca²⁺ flux was recorded for 120 seconds at a rate of measurement per two seconds. Arrows indicate time points where acetylcholine was added. Signals from more than 15 or more randomly-selected cells per group were recorded, and the results expressed as means ± S.E. of ratios of fluorescence intensity at 510 nm excited by 340 nm versus 380 nm. In B, the means of WT adrenal gland chromaffin cell signals were presented as a thin line without S.E. for better viewing. The data were analyzed by linear mixed-effect model, with genotype, individual cells, penitrem A and time as qualitative factors. P-values are indicated. Experiments were conducted at least three times. Data from representative ones are shown.