Figure 5.

Apparent affinities of Na⁺–K⁺–Cl⁻ cotransporter 2 (NKCC2) splice variants for Na⁺, Rb⁺, and Cl⁻. The data shown correspond to mean K _m ratios ± standard error among three independent studies (as described in the text). In each study, these ratios were obtained by dividing the mean K _m determined for either variant with the mean K _m determined for NKCC2F. These constants are all seen to be higher for NKCC2F and analogous between NKCC2A and NKCC2B. On the basis of our observations, V _max was also found to be higher for NKCC2F and similar between NKCC2A and NKCC2B (not shown)