ACUTE 3,4-METHYLENEDIOXYMETHAMPHETAMINE (MDMA) ADMINISTRATION PRODUCES A RAPID AND SUSTAINED SUPPRESSION OF IMMUNE FUNCTION IN THE RAT

(+/-)-3,4-methylenedioxymethamphetamine (MDMA;'Ecstasy') is a ring sub stituted phenylisopropylamine that is structurally related to both amp hetamines and hallucinogens. The unique behavioural activating propert ies of MDMA have led to its widespread abuse. MDMA induces many neuroc hemical, behavioural and endocrine alterations which closely resemble those elicited by exposure to acute stress, suggesting that MDMA could be regarded as a 'chemical stressor'. In addition to the neurochemica l, behavioural and endocrine effects of stressor exposure, it has been reported that stress produces alterations in immune function. However , to date the effects of MDMA an immune function have been restricted to in vitro investigations. In this study we report, for the first tim e, that acute in vivo administration of MDMA (20 mg/kg, i.p.) produced a rapid (within 30 min) suppression of Con A-induced lymphocyte proli feration and a profound reduction in the total leucocyte count in rats that persisted for at least 6 h following injection. These alteration s in immune function were accompanied by a significant increase in pla sma corticosterone concentrations 30 min post MDMA administration whic h had returned to baseline values within 6 h of drug administration. I n addition, there was a significant depletion in cortical 5-HT concent rations both 30 min and 6 h after MDMA administration. The results of this study provide evidence that in addition to the well established t oxic effects of MDMA on the central serotonergic system, a single admi nistration of this widely abused drug induces a rapid and sustained su ppression of immune function. (C) 1998 Elsevier Science B.V.