Fig. 3.

H⁺-ATPase inhibition attenuates the effect of DIDS on Cl⁻ flux (J_Cl) and V_T. V_T and J_Cl were measured during ENaC blockade in the presence and absence of DIDS. From these data, we calculated the change in J_Cl and V_T that follows DIDS application, or the DIDS-sensitive component of J_Cl (B) and V_T (A). In separate tubules, the experiment was repeated, but in the presence of both apical H⁺-ATPase (bafilomycin) and ENaC (benzamil) blockade. DIDS-sensitive V_T (A) and J_Cl (B) were compared in the presence and absence of apical H⁺-ATPase blockade (bafilomycin). *P < 0.05.