Figure 6. Sensitivity of cAMP-activated Cl⁻ currents to intracellular ATP removal and to extracellular H-89 administration.

Whole-cell recordings were performed in single Paneth cells equilibrated with NaCl solutions. A, representative records before and after cAMP stimulation (500 μm db-cAMP and 20 μm forskolin) using nominally ATP-free pipette solution (a) or after addition (over 30 min) of 10 μm H-89 in the pipette solution (b). Asterisks indicate application of step pulses from −100 to +100 mV in 20 mV increments (see legend to Fig. 2). B, effects of nominally ATP-free pipette solution and H-89 in the intracellular pipette solution on the mean current densities recorded at −40 mV (n = 6–31). Error bars represent s.e.m. **P < 0.01, significantly different from the control value after stimulation.