ANGIOTENSIN-CONVERTING ENZYME IN RENAL AND CEREBRAL TISSUE AND IMPLICATIONS FOR SUCCESSFUL BLOOD-PRESSURE MANAGEMENT

In addition to the classic circulating renin-angiotensin system, incre asing evidence supports the existence of local tissue renin-angiotensi n systems (vascular, cardiac, kidney, and brain) that appear to partic ipate in cardiovascular homeostasis and in the pathogenesis of cardiov ascular disorders via multiple autocrine and paracrine functions. Comp onents of local systems have been detected in cardiovascular tissues. Studies with angiotensin-converting enzyme (ACE) inhibitors provide fu rther evidence of the existence and importance of tissue renin-angiote nsin systems. The blood pressure-lowering effect of quinapril, for exa mple, correlated better with inhibition of tissue ACE (aorta) than wit h inhibition of plasma ACE. The effects of ACE inhibitors on local tis sue renin-angiotensin systems (vascular in particular) may be the cruc ial determinant of response to treatment. Newer ACE inhibitors, such a s quinapril, have favorable side effect profiles as well as apparent t issue specificity for the vascular renin-angiotensin system (and possi bly other relevant cardiovascular tissue). Differentiation among ACE i nhibitors should play an even more important role in the future for in dividualization of therapy.