Objective: To compare excretion of ions and prostaglandins by the kidney in children with noctural enuresis.
Material and methods: Thirty-two children with primary nocturnal enuresis and 23 normal children were examined. Osmolality and sodium and potassium concentrations were measured in their urine and blood serum. Prostaglandins E2, E1, and F2alpha were determined using kits for immunoenzyme analysis. Luminal and contraluminal prostaglandin secretions were studied in frog urinary bladder.
Results: Children with nocturnal enuresis have increased nocturnal diuresis and renal sodium excretion, but no increase was found in excretion of prostaglandins E2, E1, and F2alpha. Administration of sodium diclofenac before bed-time eliminated episodes of nocturnal enuresis in 37% of children; intranasal administration of Adiuretin SD had a positive effect in 69% of enuretics. In children with nocturnal enuresis there is a correlation between renal excretion of PGE2 and sodium ions; this correlation is absent in the control group children, and disappears in enuretics treated with desmopressin. To evaluate the representativeness of the data on prostaglandin secretions to urine as compared with their release to extracellular fluid, experiments on frog urinary bladder were performed: a correlation was found between prostaglandin secretion to the urinary bladder lumen and to the extracellular fluid.
Conclusions: The results of the study suggest that changes in renal function are due not to a higher secretion of prostaglandins in nocturnal enuresis but to the relative dominance of their effect as compared with other physiologically active substances that simultaneously act on renal tubular cells.