The clinical implication of tissue renin angiotensin systems

The presence, and in many cases the regulated synthesis, of components of t he renin-angiotensin system have been demonstrated in multiple tissues, ind icating the existence of tissue angiotensin-gene rating systems. These vary with respect to which renin-angiotensin system components are synthesized locally and which are taken up from plasma. Enzymes unrelated to the classi cal renin-angiotensin system may also contribute to tissue angiotensin synt hesis. However, based on the available data, the prevailing opinion that ki dney-derived renin is in all cases the only physiologically relevant renin in tissues must be revised. Also there is evidence indicating a role for ti ssue angiotensin systems in the pathogenesis of cardiovascular disease and in cardiovascular structural remodeling. The angiotensin-regulated synthesi s of aldosterone in cardiac tissue has been described, suggesting the possi bility that a renin-angiotensin-aldosterone system exists in the heart. In addition, intracellular (intracrine) sites of angiotensin action have been reported. Some of these findings have implications for therapeutics and, in particular, for the use of angiotensin converting-enzyme inhibitors and an giotensin receptor blockers. Finally, tissue angiotensin systems outside th e cardiovascular system also appear to be physiologically relevant.(C) 2001 Lippincott Williams & Wilkins, Inc.