Figure 2.

A, B, plasma Na⁺ and K⁺ concentrations measured after 10 days of experimental diet (mean ± s.e.m; n = 7–8 each diet). Mice in the low K⁺ (0.03% K⁺, 3% Na⁺) group exhibited hypernatraemia and hypokalaemia. C–F, renal Na⁺ and K⁺ excretion and clearance after 10 days of experimental diet (mean ± s.e.m; n = 7–8 each diet). Renal Na⁺ excretion (C) and clearance (E) were reduced in the low K⁺ and high K⁺ (5% K⁺, 3% Na⁺) groups. Renal K⁺ excretion (D) and clearance (F) increased with the amount of K⁺ in the diets (*P < 0.05, **P < 0.01, ***P < 0.001, one-way ANOVA).