α2-adrenoceptors in dog kidney: Autoradiographic localization and putative functions

1. The location of α₂-adrenoceptors has been examined in slide-mounted sections of dog kidney by using labelling in vitro with [³H]rauwolscine and autoradiography. 2. [³H]Rauwolscine binding in dog kidney was of high affinity, saturable, and to a single population of sites. Stereoselectivity was observed for (-)-noradrenaline and the relative affinity of a series of competing antagonists indicated binding to α₂-adrenoceptors. 3. Autoradiography of [³H]rauwolscine binding revealed localization to three areas: glomeruli, the intimal and adventitial surfaces of arcuate blood vessels and the medullary vascular bundles.