Fig. 2.

Effect of hypokalemia on urinary ammonia excretion. A: baseline urinary ammonia excretion (Pre) and urine ammonia excretion on each day of a K⁺-free diet. Urinary ammonia excretion increased each day in both control and IC-Rhbg-KO mice, but ammonia excretion was significantly less in IC-Rhbg-KO mice on each day of hypokalemia than in control mice (*P < 0.05; N = 8 in each group). B: the change in urinary ammonia excretion from baseline rate in response to a K⁺-free diet in control and IC-Rhbg-KO mice. The increase in urinary ammonia excretion was significantly less in IC-Rhbg-KO mice (N = 8 in each group on each day). C: urinary pH. Urine pH did not differ between control and IC-Rhbg-KO mice on any day of the K⁺-free diet (N = 8 in each group on each day). D: changes in the concentration of ammonia in the urine in response to hypokalemia. Urinary ammonia concentration increased significantly on each day of the K⁺-free diet in control mice, and did not change significantly from baseline urinary ammonia concentration in IC-Rhbg-KO mice (*P < 0.05 vs. baseline; N = 8 in each group).