Fig. 9.

Effect of acid loading and Na⁺-coupled electrogenic bicarbonate cotransporter A variant (NBCe1-A) deletion on urinary citrate excretion. Urinary citrate excretion was determined by NMR spectroscopy of 24-h urine collections in wild-type (WT) and NBCe1-A knockout (KO) mice before and after acid loading for 7 days. Urinary citrate excretion was significantly greater in NBCe1-A KO mice than in WT mice fed a normal diet. Acid loading significantly suppressed citrate excretion in both WT and NBCe1-A KO mice. After acid loading, there was no significant difference in citrate excretion between WT and NBCe1-A KO mice. n = 11 mice for each genotype. NS, not significant.