RENAL EFFECTS OF ANGIOTENSIN-II RECEPTOR ANTAGONIST (AT1RA)

Renin-angiotensin antagonists: The renal effects of angiotensin II rec eptor antagonists (AT1 blockers) can be compared with another class of drugs inhibiting the renin-angiotensin-aldosterone system, i.e. the a ngiotensin I converting enzyme inhibitors (ACEI). Similar but specific effects: The renal effects of these two classes Of drugs are similar but each class has specific effects explained by several mechanisms. i ) The system includes a large number of active peptides (angiotensin I I, angiotensin III, angiotensin 1-7) which exert various effects accor ding to their specific receptor(s); ii) several types of angiotensin I I receptors have been identified (AT1, AT2, AT4...). Only AT1 blockers are available in clinical practice; iii) Receptor or enzyme blockade can produce varying effects; ACE inhibition is not specific since incr eased bradykinin activity is associated with the suppression of angiot ensin peptide generation. Experimental and clinical trials: Experiment al and recent clinical studies have shown that AT1 blockers can induce , like ACEI, hypotension, renal vasodilation and natriuresis. The defi nite effects on discrete renal structures (vessels, glomeruli, tubules ) differ however in magnitude which may suggest specific indications a ccording to the pathophysiological background (renal disease, congesti ve heart failure, etc.). (C) 1997, Masson, Paris.