Effects of prostaglandin synthetase inhibition on captopril-induced changes in renal function in Bartter's syndrome.

Three patients with Bartter's syndrome were studied under metabolic ward conditions. Renal function and the reninangiotensin system were evaluated in three different settings: before and during captopril treatment and during administration of captopril and indomethacin. Captopril induced renal vasodilation with an increase in renal plasma flow by 23%. The addition of indomethacin abolished this change. Captopril increased the release of renin and the concentration of angiotensin II in plasma decreased without being completely normalized. Indomethacin thereafter reduced plasma concentration of renin, which was, however, still higher than the control level. The plasma concentration of angiotensin II did not change significantly. In conclusion, prostaglandin synthetase inhibition annihilated the effect of captopril on renal hemodynamics and renin release.