Figure 4.

Adaptation of fecal and urinary K⁺ excretion to varying K⁺ plasma levels and ion transport assessment in the colon of kcne1^−/− and wild-type mice. (A and B) Colon and renal functions were estimated by plotting mean values of plasma K⁺ levels and fecal or urinary 24-h K⁺ excretion reached by the mice on the various K⁺ diets. The overall adaptation of the kidneys is not affected in kcne1^−/− mice in contrast to the intestine whose dysfunction provokes a chronic K⁺ wasting in the feces. (C and D) Short circuit currents in colonic mucosa of kcne1^−/− and wild-type mice. A typical recording is shown in C. Arrows indicate the application of 10 μM amiloride. The averaged amiloride-sensitive calculated short circuit currents (ΔI_sc) are shown in D.