Figure 8.

(A) Outward currents in a CHO-K1 cell expressing r-eag exposed to an internal solution containing Cs⁺ as the sole charge carrier; the same internal solution was used in B–D. (B) Tail currents in a cell exposed to an external solution containing (mM) 140 CsCl, 2 CaCl₂, 2 MgCl₂, 10 Hepes/CsOH, pH 7.2. The reversal potential is ∼0 mV. (C) Instantaneous I-V plots in cells with Cs⁺ internal solution and varying extracellular K⁺ and Cs⁺ concentrations. (D) Anomalous mole fraction effect obtained from tail currents in a cell perfused with different K⁺-Cs⁺ mixtures. The tail current at −100 mV (extrapolation to t = 0 of the exponential decay of the amplitude) was normalized to the outward current at +60 mV (mean amplitude at the final 10% of the pulse).