WEB-2086 and indomethacin do not modify blood pressure fall on unclipping hypertensive rats.

1. Pretreatment with intravenous WEB-2086 (0.5 mg/kg; an antagonist of the actions of platelet activating factor; PAF) with or without indomethacin (2 mg/kg) failed to prevent or modify the fall in blood pressure following unclipping of the renal artery of anaesthetized two-kidney, one-clip hypertensive rats. 2. The same medications given to two other groups of rats 60 min after unclipping when the blood pressure had fallen to stable levels failed to reverse the fall. 3. Despite evidence that both prostanoids and PAF can be detected in increased amounts in renal venous blood after unclipping, they do not appear to mediate the reduction in blood pressure in this model of reversible hypertension.