Pharmacology of angiotensin II receptors in the kidney.

Within the kidney angiotensin II (Ang II) exerts potent effects on renal function. The intrarenal actions of Ang II include modulation of renal blood flow, glomerular filtration rate, tubular epithelial transport, renin release and cellular growth. The actions of Ang II on the kidney are mediated by specific intrarenal receptors which, based upon physical characteristics and the selective binding of non-peptide and peptide analogs may be divided into two main subtypes, termed AT1 and AT2. AT1 receptors are present within the kidneys of all species and are located predominantly in the glomerulus, the renal tubules and the renal vasculature, including the afferent and efferent arterioles. Modulation of AT1 receptors within the kidney has been shown to mediate essentially all of the known intrarenal effects of Ang II. AT1 receptors and particularly AT2 receptors are expressed in large numbers in fetal kidney where they may play a role in development and maturation. In some species, intrarenal AT2 receptors disappear shortly after birth. In those species where AT2 receptors are present in the adult kidney their role in the control of renal function has not yet been clearly defined.