Azepexole dihydrochloride (B-HT 933), a potent and selective alpha 2-adrenoceptor agonist, exhibits affinity for α2A-, α2B-, and α2C-adrenoceptor subtypes with pKis of 8.3, 7.6, and 7.5, respectively [1]. It elicits a concentration-dependent inhibition of peristaltic contractions, evidenced by an IC50 of 78.72 nM.

In normoglycemic rats, the sympathetically-induced vasopressor responses are dose-dependently inhibited by 1 and 3 μg/kg.min (i.v.) Azepexole dihydrochloride, with 10 and 30 μg/kg.min Azepexole dihydrochloride do not produce further inhibition. In diabetic rats, the electrically-induced vasopressor responses are: (i) unchanged by 1 and 3 μg/kg.min Azepexole dihydrochloride; (ii) significantly inhibited at all frequencies of stimulation by 10 μg/kg.min B-HT 933 dihydrochloride; and (iii) similarly inhibited (i.e. supramaximal inhibition) by 30 μg/kg.min Azepexole dihydrochloride [1].