alpha 2-Adrenoceptors in dog kidney: autoradiographic localization and putative functions.

The location of alpha 2-adrenoceptors has been examined in slide-mounted sections of dog kidney by using labelling in vitro with [3H]rauwolscine and autoradiography. [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 alpha 2-adrenoceptors. 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.