Angiotensin II and the control of cardiovascular structure

The structure and function of the vessel wall are dependent on the balance of several counteracting forces, i.e., vasoconstricting versus vasodilating , growth-promoting versus growth-inhibiting, and proapoptotic versus antiap optotic. In a normal healthy vessel, these factors are closely balanced. Ho wever, under pathophysiologic conditions this balance is upset, resulting i n the development of vascular hypertrophy and the generation of vascular le sions. For example, during the initiation and progression of atherosclerosi s, there is an imbalance in a number of these processes, resulting in a pro atherogenic state. Similarly, processes involved in maintaining the structu re and function of the cardiac wall are under tight control and, when the c ontrol is upset, can result in left ventricular hypertrophy, with subsequen t decreases in cardiac function and the development of failure. Evidence su ggests that angiotensin II (AngII), acting via a family of receptors, plays an important role in the regulation of structure and function in both the heart and vessel wall; under pathologic conditions, the ability of the hear t and vessel wall to generate AngII is increased, because of increased angi otensin-converting enzyme expression. In this review, the potential role of AngII in the regulation of cardiac and vascular structure and function is discussed.