ATP does not inhibit steady-state CLC-1 current in patches excised from tsA201 cells. The pHi was 6.8. (A) Steady-state CLC-1 current in the absence (control) and in the presence of 3 mM ATP. (B) Effects of 3 mM ATP on the Poc-V curve of CLC-1 expressed in tsA201 cells. Data points were obtained from the experiments as those shown in A.