title: Androgenic-anabolic steroids blunt morphine-induced c-fos expression in the rat striatum: possible role of beta-endorphin.
abstract: Self-administration of large doses of androgenic-anabolic steroids (AAS) in a significant portion of the population suggests that these agents are drugs of abuse. However, acute administration of AAS did not induce striatal immediate-early genes (IEG) expression in male rats, indicating that AAS do not share a common mechanism of action with other drugs of abuse. Surveys have indicated that people who abuse AAS are more likely to self-administer other drugs of abuse than do people who do not take AAS. In the present study, chronic administration of AAS blunted the striatal c-fos response to morphine, indicating that AAS can alter the molecular responses to at least one drug of abuse. Chronic administration of AAS also increased the content of beta-endorphin in the midline thalamus, suggesting a possible mechanism by which AAS may modulate the response to morphine through regulation of thalamo-striatal neurons.
authors.affiliation: Department of Structural and Cellular Biology SL-49, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA, USA. harlanre@mailhost.tcs.tulane.edu
authors.forename: R E
authors.initials: RE
authors.lastname: Harlan
authors.forename: H E
authors.initials: HE
authors.lastname: Brown
authors.forename: C S
authors.initials: CS
authors.lastname: Lynch
authors.forename: D
authors.initials: D
authors.lastname: D'Souza
authors.forename: M M
authors.initials: MM
authors.lastname: Garcia
mesh_terms: D045930:Anabolic Agents / Q000008:administration & dosage*; D000818:Animals; D003342:Corpus Striatum / Q000187:drug effects* / Q000378:metabolism; D004334:Drug Administration Schedule; D015870:Gene Expression / Q000187:drug effects; D017781:Genes, Immediate-Early; D007150:Immunohistochemistry; D008297:Male; D020644:Midline Thalamic Nuclei / Q000187:drug effects / Q000378:metabolism; D009020:Morphine / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D009412:Nerve Fibers / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis*; D016755:Proto-Oncogene Proteins c-jun / Q000096:biosynthesis; D051381:Rats; D017207:Rats, Sprague-Dawley; D001615:beta-Endorphin / Q000187:drug effects / Q000378:metabolism*
chemical_list: D045930:Anabolic Agents; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D001615:beta-Endorphin; D009020:Morphine