ANGIOTENSIN-CONVERTING ENZYME IN CARDIOVASCULAR AND ADRENAL TISSUES AND IMPLICATIONS FOR SUCCESSFUL BLOOD-PRESSURE MANAGEMENT

Components of the renin-angiotensin system, and the ability to synthes ize these components locally, have been demonstrated in cardiovascular tissues. Locally generated angiotensin II may affect vascular tone, r egional blood flow, cardiac contractility, and vascular and cardiac gr owth. Local renin-angiotensin systems may exert autocrine and paracrin e functions, whereas the circulating system serves an endocrine functi on. Use of angiotensin-converting enzyme (ACE) inhibitors has provided further clarification of the activities of local renin-angiotensin sy stems. Tissue and systemic effects of these agents may prove equally i mportant in determining their clinical efficacy. Experiments with quin april demonstrated that inhibition of vascular ACE was a significant c omponent of the antihypertensive effect of the drug. Differences at th e tissue level may have implications for the efficacy and tolerability of a particular agent. Improved individualization of therapy may be a ccomplished by the use of newer ACE inhibitors with very favorable sid e effects profiles and tissue specificity. The newest agent, quinapril , appears to exert an important effect on vascular converting enzyme.