CFTR and cystic fibrosis: Fluid secretory rates (Controls vs. CF, in pl/min/gland) were as follows: 3 μM forskolin: 9.2±2.2 vs. 0.6±0.3; 1 μM carbachol: 143.5±35.5 vs. 52.2±10.3; 3 μM forskolin + 0.1 μM carbachol: 25.8±5.8 vs. CF 4.5±0.9.