Angiotensin converting enzyme inhibitors: inhibition of growth, a novel mechanism of action.

Angiotensin II, a known vasopressor agent, recently has been implicated as a growth factor in the heart and vascular smooth muscle. Angiotensin converting enzyme (ACE) inhibitors, which block angiotensin II synthesis, have been found to prevent or reverse cellular growth in the heart and vasculature--a novel mechanism of action. Further study is required to determine the precise mechanisms through which angiotensin II promotes growth as well as the mechanisms through which ACE inhibitors block growth. Large scale clinical trials are needed to delineate further the effectiveness of ACE inhibitors in humans, especially regarding vascular smooth muscle growth.