[3H]rauwolscine (α-yohimbine): A specific antagonist radioligand for brain α2-adrenergic receptors Academic Article uri icon


  • [3H]Rauwolscine, a specific and potent alpha 2-antagonist radioligand, was used to characterize alpha 2-receptor binding in bovine cerebral cortex. [3H]Rauwolscine binding was reversible, stereospecific, and saturable. Association, dissociation, and saturation studies revealed one site interactions (k -1/k+1 = 1.2 nM, KD = 2.5 nM, Bmax = 160 fmol/mg protein) and competition studies indicated that [3H]rauwolscine labeled the alpha 2-receptor. Agonists inhibited [3H]rauwolscine binding in a shallow, GTP-sensitive manner. These results suggest that [3H]rauwolscine specifically labels both the high and low affinity states of the alpha 2-receptor in brain membranes.

publication date

  • December 1981