Fig. 3.

Urinary ammonia excretion, urine pH, and titratable acid excretion in response to HCl-induced metabolic acidosis. Mice were housed in metabolic cages, and urine was collected daily under mineral oil. A: urinary ammonia excretion. While on a normal diet, urinary ammonia excretion was not significantly different between CD-Rhbg/Rhcg-KO and C mice. After addition of HCl to their chow, urinary ammonia excretion increased significantly on the first day in C mice and continued to increase to a maximum on day 6. In CD-Rhbg/Rhcg-KO mice, urinary ammonia excretion also increased significantly on the first day of acid loading, did not peak until day 6, and remained significantly less than in C mice on days 1–5. B: urine pH. Urine pH was significantly lower in CD-Rhbg/Rhcg-KO mice than in C mice on days 1, 3, and 5 of acid loading. C: titratable acid excretion under basal conditions and in response to acid loading. There was no significant difference in titratable acid excretion between genotypes, either at baseline, or on either day 2 or 7 of acid loading. Values are means ± SE; n = 6/group. *P < 0.05 vs. C.