CHARACTERISTIC LOCALIZATION OF ALPHA(1)-ADRENOCEPTORS AND ALPHA(2)-ADRENOCEPTORS IN THE HUMAN KIDNEY

1. The localization of alpha-adrenoceptors in the plasma membranes of human kidney were investigated by radioligand binding, using an alpha1 -antagonist, [H-3]-bunazosin, and an alpha2-antagonist, [H-3]-rauwolsc ine. 2. Both the maximum binding (B(max)) and dissociation constant (K (d)) of [H-3]-bunazosin were greater in the cortex than in the medulla . The B(max) of [H-3]-rauwolscine in the medulla was greater than in t he cortex. 3. Thus, alpha1-adrenoceptors appeared to be localized pred ominantly in the cortex, while the alpha2-adrenoceptors were mainly pr esent in the medulla of the human kidney.