Short-term effects of 3,4-methylenedioximethamphetamine on noradrenergic activity in locus coeruleus and hippocampus of the rat.
This study was undertaken to investigate the effects of the administration of 3,4-methylenedioxymethamphetamine (MDMA) on the locus coeruleus firing rate, on the sensitivity of the alpha(2)-adrenoceptors which regulate neuronal activity and on the in vivo tyrosine hydroxylase activity in hippocampus. The basal firing rate was not modified by either a single dose or repeated doses of MDMA, although the latter produced a shift to the right in the dose-response curve for clonidine-induced inhibition of the firing rate (ED(50) increased by 59%) and a reduction in tyrosine hydroxylase activity (20%) in the hippocampus. However, 8 days after the final dose alpha(2)-adrenoceptor sensitivity and tyrosine hydroxylase activity had returned to control values. Our results show a desensitization of alpha(2)-adrenoceptors in locus coeruleus and the existence of short-term changes in the noradrenergic system.
Arrue
Aurora
A
Department of Pharmacology, Faculty of Medicine and Odontology, University of the Basque Country, 48940-Leioa, Vizcaya, Spain.
Ruiz-Ortega
José Angel
JA
Ugedo
Luisa
L
Giralt
M Teresa
MT
D018759:Adrenergic Uptake Inhibitors / Q000494:pharmacology*; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000704:Analysis of Variance; D000818:Animals; D001958:Brocresine / Q000494:pharmacology; D003000:Clonidine / Q000494:pharmacology; D004295:Dihydroxyphenylalanine / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D010134:Fenclonine / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D008125:Locus Coeruleus / Q000187:drug effects* / Q000378:metabolism; D008297:Male; D018817:N-Methyl-3,4-methylenedioxyamphetamine / Q000494:pharmacology*; D009474:Neurons / Q000187:drug effects / Q000378:metabolism; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D018341:Receptors, Adrenergic, alpha-2 / Q000187:drug effects; D014446:Tyrosine 3-Monooxygenase / Q000187:drug effects / Q000378:metabolism
D018759:Adrenergic Uptake Inhibitors; D000316:Adrenergic alpha-Agonists; D004791:Enzyme Inhibitors; D018341:Receptors, Adrenergic, alpha-2; D001958:Brocresine; D004295:Dihydroxyphenylalanine; D014446:Tyrosine 3-Monooxygenase; D018817:N-Methyl-3,4-methylenedioxyamphetamine; D003000:Clonidine; D010134:Fenclonine; D009638:Norepinephrine