Effect of endothelin on angiotensin converting enzyme activity in cultured pulmonary artery endothelial cells

We studied the effects of endothelin on angiotensin converting enzyme (ACE) in cultured pulmonary artery endothelial cells. ACE activity was increased 2.5-fold by the addition of 1 x 10(-8) mol/l endothelin-1. Endothelin-1 also stimulated calcium influx and phospholipase C activity in a dose-dependent manner. Calcium influx, phospholipase C and ACE activity were suppressed 60-70% in the presence of endothelin-1 (10(-10) to 10(-6) mol/l) by 50 microliters neomycin. These results suggest that ACE was stimulated by endothelin-1 and that its activity may be closely related to phosphatidylinositol turnover stimulated by endothelin-1.