Osmolality and Prox1 expression.

<p>(A) Urine osmolalities were measured in mice at postnatal days 1, 4, 7, 14, 21, 28, and 56 on <i>ad libitum</i> fluid intake. Within 1 week after birth, urine osmolality was no more than 500 mOsmol/kg H₂O; it began to increase from day 14, reaching peak levels at days 28 and 56. Each bar represents the mean of three independent experiments; error lines are SD. (B) At all developmental stages, Prox1 expression correlated closely with urine osmolality. R² = 0.8870; P = 0.0015