Preeclampsia, the Renin-Angiotensin-Aldosterone System and beyond

Abstract

__Abstract__ The renin-angiotensin-aldosterone system (RAAS) plays an essential role in the regulation of blood pressure and body fluid homeostasis, but also contributes importantly to the pathophysiology of hypertension, renal disease and heart failure. Clinically, the RAAS is of great interest as inhibition at different levels has been proven to be an effective therapy for hypertension, cardiovascular and renal disease. Angiotensin II mediates its effects via angiotensin II type 1 (AT1) and angiotensin II type 2 (AT2) receptors. AT1-receptors are widely expressed throughout the body and mediate the well-known effects of angiotensin II, including vasoconstriction, sympathetic nervous system activation and sodium and water retention. While experimental studies show that stimulation of the AT2-receptor counteracts these effects by inducing vasorelaxation and natriuresis in healthy animals, our knowledge about AT2-receptor function in humans is limited to a few studies, showing, at most, modest vasodilatory effects upon AT2-receptor stimulation. In contrast to the beneficial effects, recent studies suggest