Rauwolscine hydrochloride (Isoyohimbine hydrochloride) , a natural alkaloid, is a specific and reversible α2-adrenergic receptor antagonist (Ki: 12 nM) [1]. It is a stereoisomer of yohimbine, which potently antagonizes both α1- and α2-adrenergic receptors [1]. Rauwolscine hydrochloride also acts as a receptor antagonist at the serotonin 5-HT2B receptor (Ki: 14.3 nM) and as a weak partial agonist at 5-HT1A (IC50: 1.3 μM) [3]. The α2-adrenergic receptor has diverse physiological functions and antagonists like rauwolscine have numerous applications, including the modulation of mood and behavior [5].

α2-adrenoceptor:12 nM (Ki)

[3H]Rauwolscine与α2肾上腺素受体的结合是可逆的、立体特异性的，并且可饱和。[3H]Rauwolscine在脑膜中特异性地标记α2肾上腺素受体的高亲和力状态和低亲和力状态[1]。[3H]Rauwolscine还作为5-HT1A受体激动剂，表明rauwolscine（以及yohimbine）在5-HT自受体水平上具有激动剂属性[2]。当使用[3H]5-HT作为放射性配体时，发现rauwolscine对人类受体有相对较高的亲和力（Ki：14.3/35.8 nM，对于人和鼠）[3]。饱和度研究显示，[3H]Rauwolscine的亲和力在鼠、兔、鼠、狗（2.33-3.03 nM）中相似，但在人类中显著更高（0.98 nM）[4]。

Fresh bovine frontal cortex is incubated in triplicate with [3H]Rauwolscine (82 Ci/mM, diluted). Incubation is terminated by filtration under reduced pressure over filters, which are then rinsed with ice-cold Tris-HCl buffer, dried overnight and added to disposable glass mini vials containing 3.0 mL of a 95% Econofluor/5% Protocol solution. Samples are counted by liquid scintillation spectrometry with an efficiency of 32%. (-)- [3H]Epinephrine binding to bovine cortex membranes is conducted at 25°C[1].