Benefits of ACE Inhibition Beyond the Fall in Blood Pressure

Benefits of ACE Inhibition Beyond the Fall in Blood Pressure 

The randomized controlled clinical trials performed by Freis and his colleagues at the Veterans Administration Hospitals have provided some of the first solid evidence that moderate permanent hypertension has an improved prognosis when actively treated by sodium depletion (hydrochlorothiazide), by interruption of the sympathetic nervous system (reserpine) and with a vasodilator (hydralazine) (262). In parallel, the beneficial effects of this triple therapy were demonstrated in spontaneously hypertensive rats by the spectacular prevention and cure of their cardiac, vascular, and renal lesions (263). 

Another example includes the specific effects of ACE inhibition on the prevention of renal insufficiency. In comparison with triple therapy, the reduction of intraglomerular pressure induced by ACE inhibitors (277) as well as by angiotensin II antagonists (278), is much more marked, and it protects the kidney from glomerular, vascular, and tubu-lointersitial lesions observed in various experimental models, especially renal ablation and diabetes (279). Besides the fall in efferent arteriole resistance, the interruption of the RAS inhibits tubulointerstitial inflammation and the production of cytokines, which are observed in these various experimental models (280, 281). 

Before opposing two interpretations of a phenomenon that is not yet completely demonstrated (cardiovascular and renal benefits independent of a fall in blood pressure), it is worthwhile to reemphasize that the clinical measurement of blood pressure by physicians or nurses is an insensitive and imprecise method for investigating the human organism s hemodynamics. Failure to detect a fall in blood pressure by this method does not eliminate a hemodynamic effect. The cellular actions of angiotensin II (290) and its hemodynamic effects are so closely linked that attributing cardiovascular changes to one at the expense of the other is probably an intellectual exercise more than a realistic approach. 

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XI. Benefits of ACE Inhibition Beyond the Fall in Blood Pressure. 45... 

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