Local production of kinins contributes to the endothelium dependent relaxations evoked by converting enzyme inhibitors in isolated arteries.

The angiotensin converting enzyme (ACE) inhibitor perindoprilat evokes endothelium-dependent relaxations in perfused isolated canine arteries. Kininogens, the precursors of bradykinin, elicit endothelium-dependent relaxations which are potentiated by perindoprilat, inhibited by B2-kinin antagonists and partially impaired after inhibition of NO synthase. These observations suggest that locally produced kinins may stimulate the production of NO and endothelium-derived hyperpolarizing factor, and that this action is potentiated by ACE inhibitors.