EFFECT OF CIS-UNSATURATED FATTY-ACIDS, PROSTAGLANDINS, AND FREE-RADICALS ON ANGIOTENSIN-CONVERTING ENZYME-ACTIVITY IN-VITRO

Angiotensin-converting enzyme (ACE) is known to play an important role in the pathobiology of human essential hypertension. Similarly, cis-u nsaturated fatty acids, prostaglandins, and free radicals are believed to play a role in the control of blood pressure. It was observed that all the cis-unsaturated fatty acids tested can inhibit ACE activity t o a significant degree. On the other hand, prostaglandins and free rad icals, superoxide anion, hydrogen peroxide, and hydroxyl radical did n ot show significant inhibitory effects on ACE activity in vitro. But, the nitric oxide donor sodium nitroprusside showed a potent inhibitory action on ACE activity, suggesting that one of the possible mechanism (s) by which nitric oxide can bring about its anti-hypertensive action might be by modulating ACE activity in addition to its direct vasodil ator action. These results indicate that there is a close interaction among ACE activity, cis-unsaturated fatty acids, and nitric oxide, whi ch may have relevance to the pathobiology of human essential hypertens ion.