Figure 1.

The different effects of acid-load (A–D) and fludrocortisone (E–H) on urinary acid excretion in WT and V1aR^−/− mice. The administration of 0.28 M NH₄Cl decreased the urine pH (A) and increased the titratable acid (B), ammonium (C), and net acid excretion (D) in WT (dotted line) and V1aR^−/− mice (solid line). The increase in urinary ammonium and net acid excretion was greater in WT mice than in V1aR^−/− mice. In contrast, fludrocortisones increased the urine pH (E), ammonium (F), and net acid excretion (G) while decreasing the titratable acid excretion (H). The effects of fludrocortisones were more significant in V1aR^−/− (solid line) than in WT mice (dotted line). Mean ± SEM. n = 4 to 6. *P < 0.05 and **P < 0.01 versus WT mice; ††P < 0.05 versus day 1.