THE EFFECT OF ADRENALECTOMY ON MDMA-INDUCED DOPAMINE RELEASE IN THE STRIATUM AS MEASURED BY INVIVO MICRODIALYSIS AND DEPLETION OF SEROTONIN

The effect of adrenalectomy (ADX) on the increase in the extracellular concentration of dopamine (DA) in the striatum produced by the peripheral administration of 3,4-methylenedioxy-methamphetamine (MDMA) was examined using in vivo microdialysis. MDMA (20 mg/kg) significantly increased the extracellular concentration of DA in the striatum of both ADX and SHAM animals. There was no significant difference between the ADX and SHAM animals with respect to MDMA-induced increase in DA concentrations. The time-course effect of MDMA on the concentrations of serotonin (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) also was examined in forebrain regions of ADX and SHAM animals. MDMA (20 mg/kg) significantly decreased the concentrations of 5-HT and 5-HIAA in the hypothalamus, frontal cortex, hippocampus and striatum 3 hr and 7 days following administration of MDMA (20 mg/kg). With the exception of the frontal cortex, there was no significant difference between ADX and SHAM animals with respect to the acute (3 and 24 hr) and long-term (7 day) depletion of 5-HT and 5-HIAA content produced by the administration of MDMA. These data are suggestive that ADX has no effect on MDMA-induced release of DA in the striatum and minimal protective effect of the 5-HT neurotoxicity produced by the administration of MDMA. Thus, corticosterone does not play a significant role in MDMA-induced 5-HT and 5-HIAA depletion.