Bradykinin receptors localized by quantitative autoradiography in kidney, ureter, and bladder

We have localized high affinity [3H]bradykinin receptor binding sites by in vitro autoradiography in kidney, ureter, and bladder of the guinea pig. The peptide pharmacology of the binding sites corresponds to that of high affinity physiological bradykinin receptors previously described (Manning, D. C., R. Vavrek, J. M. Stewart, and S. H. Snyder. J. Pharmacol. Exp. Ther. 237:504-512, 1986). In the kidney, receptors are concentrated in the medulla with negligible binding in the cortex. Medullary receptors are localized to the interstitium just beneath the basal membrane of collecting tubule cells and between tubules. In the ureter and bladder, receptors are confined to the lamina propria just beneath the epithelial layer. Localizations in the kidney may relate to the diuretic and natriuretic actions of bradykinin. Ureteral and bladder receptors may be associated with a role of bradykinin in pain and inflammation.