Effect of Lisinopril on Circulating Neuropeptides in Essential Hypertensive Patients

It has been suggested that the vasodilator neuropeptides may be involved in both the control of blood pressure and the antihypertensive effect of the angiotensin-converting enzyme inhibitor captopril (Ajayi et al. 1985). The angiotensin-converting enzyme has many similarities to a membrane-bound enzyme which inactivates metenkephalin (Beruck and Marks 1979), and captopril has been said to increase enkephalin levels in patients with migraine (Baldi et al. 1983). In experimental models angiotensin-converting enzyme inhibition has also been shown to block the increase in plasma beta-endorphins produced by angiotensin I (Beuers et al. 1982). In normal volunteers angiotensin-converting enzyme inhibition with enalapril did not alter metenkephalins (VandenBurg et al. 1985), and in hypertensive patients beta-endorphins were not affected (VandenBurg et al. 1984).