Fig. 1.

Body water balance and urine osmolality in female WT (n = 10), LXRα^−/− (n = 10), and LXRβ^−/− (n = 10) mice. Mice were housed in metabolic cages with free access to food and water for 24 h. (A) The daily urine volume is significantly higher in LXRβ^−/− mice than in WT mice. (B) The 24-h urine osmolality, an indication of diluted urine, is significantly lower in LXRβ^−/− mice than in WT mice. (C) The 24-h water intake is higher in LXRβ^−/− mice. (D) The 24-h urine volume of WT and LXRβ^−/− mice at age 2, 4, 9, 13, and 17 mo (n = 8 each group). The onset of polyuria appears to occur at age 4 mo. Data are presented as mean ± SEM; *P < 0.05; **P < 0.001 versus WT.