Bartter's syndrome without hyperplasia of the juxtaglomerular apparatus, treated with indomethacin.

The present report describes a case of potassium-wasting nephropathy with the physiological and endocrinological findings that are typical for Bartter's syndrome (BS). However, the renal juxtaglomerular apparatus showed no hyperplasia at two renal biopsies two years apart. The short-term (9 days) effect of indomethacin in combination with spironolactone was a suppression of hyperreninemia and hyperaldosteronism and an increase in vascular sensitivity to angiotensin II associated with potassium and sodium retention. Subsequently, on indomethacin alone, potassium balance was obtained on a lower level with persistent hypokalemia and persistent renal potassium leakage. Hypokalemia persisted during long-term (9 months) treatment with indomethacin despite normalization of the activity of the renin-aldosterone system. The results indicate that indomethacin as long-term treatment may be ineffective in maintaining a normal potassium balance in BS.