Angiotensin II and the kidney

: Angiotensin II (AngII) plays a central role for maintenance of GFR and Na balance particularly in volume depletion, when AngII preferentially increases the resistance of efferent arterioles as compared to afferent arterioles, enhancing the glomerular perfusion pressure. In addition, AngII enhances tubular reabsorption of sodium in proximal tubules directly and indirectly as a consequence of glomerulotubular balance. AngII also stimulates Na reabsorption in the collecting ducts by stimulating the release of aldosterone from the adrenal cortex. AngII augments tubuloglomerular feedback. Recently, it has been shown that AngII has a variety of non-hemodynamic effects on cell growth and differentiation as well as inflammatory responses, and it has been speculated that the increased renin-angiotensin, not only systemic but local one, may be responsible for the pathogenesis of a number of renal diseases.