Location of 125I‐angiotensin II receptors on rat kidney cortex epithelial cells

Angiotensin II (AII) stimulates active Na+ extrusion from Na+ loaded renal cortex slices. Specific high affinity 125I-AII binding sites in partially purified basolateral and brush-border epithelial membranes exhibit a KD of 0.88 nM and Bmax of 321.13 fmol mg-1 protein. Separation and purification of brush-border membranes yielded high affinity 125I-AII binding sites with KD of 1.02 nM and Bmax of 56.6 fmol mg-1 protein. Angiotensin II receptors of the same affinity are present on renal cortex brush-border and basolateral membranes but a greater proportion are located on the latter. These receptors may be involved in the direct control of Na+ and water transport by AII.