The influence of selective and nonselective prostaglandin inhibition on renin.

The finding that sulindac, in contrast to indomethacin, does not inhibit renal prostaglandins (PGs) can offer the means to study the role of systemic and/or renal PGs in the control of renin. Therefore we studied, using a randomized cross-over design, the influence of treatment with sulindac and indomethacin on plasma renin activity (PRA) of essential hypertensive patients, which was measured either after standing or after chronic captopril and chlorthalidone administration. In the captopril-treated group, serum thromboxane B2 (TXB2) and urinary 6-keto-PGF1alpha were significantly reduced by indomethacin, while sulindac reduced only serum TXB2. PRA was significantly reduced by indomethacin in the three groups and by sulindac only in standing and captopril-treated patients. These findings suggest that systemic PGs are mainly involved in the control of renin during standing and angiotensin-converting enzyme (ACE) inhibition, while mainly renal PGs play a role in the control of renin during chronic thiazide-like diuretic administration.