Urinary excretion of prostaglandins and electrolytes in developing children.

A longitudinal study of the urinary excretion of prostaglandins (PG's) E and Falpha was performed in 55 healthy children aged from 1 to 114 months. In addition, the urinary PG's and electrolytes were studied in 6 children with Bartter's syndrome before and after an oral treatment with indomethacin. In normal children, both urinary PGE and PGF alpha increased with age, more markedly before 24 months of age. During this period, a positive and significant correlation was found with the urinary osmolality (r = 0.61, N = 16, P less than 0.05 for PGE; r = 0.82, N = 16, P less than 0.001 for PGF alpha). At every age, the urinary PG's were related to the potassium excretion (r = 0.68, N = 55, P less than 0.001 for PGE; r = 0.65, N = 55, P less than 0.002 for PGFalpha) but not to the natriuresis. In children with Bartter's syndrome, the increased urinary excretion of PGE, PGFalpha and potassium when the natriuresis was either decreased or increased after treatment. These results suggest that the renal PG's might play a role in the control of potassium excretion by the kidney. In addition, the determination of normal values in different age groups appears necessary for an accurate interpretation of the urinary PG's.