Renin-angiotensin-aldosterone system: fundamental aspects and clinical implications in renal and cardiovascular disorders.

The renin-angiotensin-aldosterone system (RAAS) exerts a principal influence in maintaining vascular tone, optimal salt and water homeostasis, and forward cardiac output in human beings. Overactivity of the RAAS can lead to pathologic consequences in states of diabetic nephropathy, hypertension, renal artery stenosis, left ventricular hypertrophy, coronary atherosclerosis, myocardial infarction, and congestive heart failure. In addition to fluid and hemodynamic effects, the RAAS may have a critical role in the activation of the sympathetic nervous system, the progression of atherosclerosis, the dysregulation of endothelial function, and the inhibition of the fibrinolytic system. Accumulated basic and clinical evidence supports the use of inhibitors of the RAAS, including aldosterone antagonists, angiotensin-converting enzyme inhibitors, and angiotensin receptor blockers, in treating hypertension, improving diabetic nephropathy, preventing or ameliorating congestive heart failure, and optimizing the prognosis after myocardial infarction.