Investigation of the prejunctional α2‐adrenoceptor mediated actions of MDMA in rat atrium and vas deferens
British Journal of Pharmacology November 1, 1999 Aisling Lavelle, Valerie Honner, James R. Docherty 55 citations
MDMA (ecstasy) acts as an agonist at alpha-2 adrenoceptors in the rat peripheral nervous system, inhibiting noradrenaline release and nerve-stimulated contractions. In atrial slices, MDMA (10 µM) reduced tritium release evoked by electrical stimulation, an effect blocked by the alpha-2 antagonist yohimbine. In the epididymal vas deferens, MDMA inhibited contractions with a pD2 of 5.88, antagonized by yohimbine but not by a serotonin receptor antagonist. In the prostatic vas deferens, yohimbine converted MDMA's inhibition into potentiation of contractions. Radioligand binding showed MDMA had similar affinities for alpha-2B, alpha-2C, and alpha-2D adrenoceptor subtypes, with pKi values around 5.1–5.3.