Fig. 4.

Transient receptor potential vanilloid type 4 (TRPV4)^−/− mice develop urinary acidification when fed a K⁺-deficient diet. A: summary graph showing the comparison of urinary pH in wild-type (WT) and TRPV4^−/− mice in metabolic cages maintained on a regular K⁺ diet (0.9% K⁺) and in response to a K⁺-deficient diet (<0.01% K⁺) for 1 or 2 days. B: summary graph of time course changes in spot urinary pH for WT and TRPV4^−/− mice kept on K⁺-deficient (<0.01% K⁺), regular K⁺ (0.9% K⁺), and high-K⁺ (5% K⁺) diets, as indicated by the respective bars at the top. Values are means ± SE; n, number of experimental animals for each group. *Significant decrease versus the respective value in WT mice.