Fig. 2

Ionic basis for the increase in I _sc induced by 100 nM serosal trypsin. Bumetanide (100 μM, serosal) and 5-nitro-2-(3-phenylpropylamino)benzoic acid (NPPB; 100 μM, mucosal) were added, or Cl ⁻ was removed (from both the mucosal and serosal bathing solutions) 20 min before adding 100 nM trypsin to the serosal side. Peak values for the increases in I _sc (ΔI _sc) induced by trypsin were determined and are expressed as a percentage of the control response obtained in the adjacent tissue. Each data value is presented as the mean ± SE, with n = 4 for bumetanide and n = 5 for the other compounds. *0.01 < P < 0.05 and ***P < 0.001, compared with the control response that had been determined in adjacent tissue by a paired t test