Fig. 1.

Differential effects of calcium and cAMP agonists on ASL pH in CF nasal epithelia under normal and inflammatory conditions. (A) Schematic overview of the fluorescent staining of the ASL with cell-impermeant pH-sensitive dye. (B) Summary ASL pH traces from CF epithelia under normal (black trace) or inflammatory conditions (IL-4,10 ng/mL for 48 h, red trace). Baseline ASL pH was measured for ~2 h, followed by the addition of carbachol (CCh, 50 µM), and then forskolin (FSK, 10 µM) as indicated. (C) Baseline ASL pH. This was calculated as the average of five time points before the addition of CCh (n = 21, three donors, unpaired t test). (D) ASL pH after acute addition of carbachol (50 µM). This was calculated as the average of five time points after the addition of CCh. (n = 21, three donors, unpaired t test). (E) ASL pH after acute addition of forskolin (10 µM). This was calculated as the average of five time points 2 h after the addition of FSK. (n = 21, three donors, unpaired t test). Data are presented as mean ± SD; **P < 0.01 and ****P < 0.0001.