Hormonal factors influencing fractional excretion of filtered sodium in normal children.

Fractional excretion of filtered sodium (FENa), plasma renin activity (PRA), urinary kallikrein excretion and main urinary metabolite of prostaglandin F2 alpha (PGF MUM) excretion were measured to evaluate the relationship between FENa and these hormonal factors in 33 healthy children aged 8 to 15 years. FENa showed a significant negative correlation with PRA and PGF MUM excretion (P less than 0.001, P less than 0.01, respectively), suggesting that PRA and PGF MUM are useful investigations in evaluating FENa. Especially PRA is often measured routinely and should be measured first, which may provide useful pathophysiological information on the genesis of abnormal FENa.