Fig. 1.

Epithelial Na⁺ channel (ENaC) activity in mice with knockout of the HKα₁ isoform of H⁺,K⁺-ATPase (HKα₁^−/−) is uncoupled from Na⁺ intake. Representative single-channel current traces for ENaC in wild-type (WT; A) and HKα₁^−/− mice (B) during high-Na⁺ dietary (2.0%) conditions. ENaC channel numbers, N, open probability, P_o, and activity, NP_o, are shown for WT and HKα₁^−/− mice (C–E). Data are shown as means ± SE. Numbers of patches are shown in columns. *P < 0.05 vs. 0.32% Na⁺; †P < 0.05 vs. WT, same dietary Na⁺ condition.