Rauwolscine (hydrochloride)

Rauwolscine hydrochloride is a potent and specific α2 adrenergic receptor antagonist with a K_i of 12 nM. IC50 & Target: Ki: 12 nM (α2 adrenergic receptor)^[1] In Vitro: [³H]Rauwolscine binding to α2 adrenergic receptor is reversible, stcreospccific, and saturable. [³H]Rauwolscine specifically labels both the high and low affinity states of the α2 adrenergic receptor in brain membranes^[1]. [³H]Rauwolscine also behaves as a 5-HT1A receptor agonist and this conclusion is compatible with earlier functional studies, indicating that rauwolscine (as well as yohimbine) has agonistic properties at the level of 5-HT autoreceptors^[2]. When using [³H]5-HT as a radioligand, rauwolscine is determined to have relatively high affinity for the human receptor (K_i human=14.3 nM, K_i rat=35.8 nM)^[3]. Saturation studies shows that the affinity of [³H]Rauwolscine is similar in mouse, rat, rabbit, dog (2.33-3.03 nM) except man where it is significantly higher (0.98 nM) ^[4].