Figure 3.

cAMP activated Cl^- currents in MAEC A. Slow activation of the CFTR currents. Currents values were obtained form linear voltage ramps and were measured at +50 mV (holding potential, V_H = 0 mV). B. Instantaneous current-voltage relationships measured from voltage ramps at the times indicated by solid circles (a and b) in panel A. C. Difference current, b-a, from the current measured after and before stimulation with the cAMP elevating cocktail. From such protocols current density was measured for the wild type and the trp4-deficient MAEC (see figure 4). D. Block of the cAMP activated current by 50 μM glibenclamide (measured from voltage ramps at +50 mV, V_H = 0 mV)