Studies on the effect of two angiotensin-converting enzyme inhibitors, captopril and cilazapril, on platelet and vascular prostaglandin metabolism in vivo.

We have studied in 12 healthy volunteers the effects of two angiotensin-converting enzyme (ACE) inhibitors, captopril and cilazapril, on vascular and platelet prostaglandin metabolism, in a double-blind, placebo-controlled, randomized cross-over study. Formation of 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha) and thromboxane B2 (TxB2) was measured locally at the site of a microvascular injury. Similar amounts of TxB2 and 6-keto-PGF1 alpha were generated following administration of either ACE inhibitor as compared to placebo. It is concluded that neither captopril nor cilazapril significantly influence vascular and platelet prostaglandin metabolism.