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.