ANABOLIC-ANDROGENIC STEROIDS INCREASE BETA-ENDORPHIN LEVELS IN THE VENTRAL TEGMENTAL AREA IN THE MALE-RAT BRAIN

Citation
P. Johansson et al., ANABOLIC-ANDROGENIC STEROIDS INCREASE BETA-ENDORPHIN LEVELS IN THE VENTRAL TEGMENTAL AREA IN THE MALE-RAT BRAIN, Neuroscience research, 27(2), 1997, pp. 185-189
Citations number
24
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Neurosciences
Journal title
ISSN journal
0168-0102
Volume
27
Issue
2
Year of publication
1997
Pages
185 - 189
Database
ISI
SICI code
0168-0102(1997)27:2<185:ASIBLI>2.0.ZU;2-2
Abstract
The levels of beta-endorphin and Met-enkephalin-Arg-Phe (MEAP) immunor eactivity in various brain regions (including amygdala, cortex, hippoc ampus, hypothalmus, nucleus accumbens, pituitary and ventral tegmental area) were studied in male rats subjected to dialy intramuscular inje ctions during 14 days of high doses (5 and 15 mg/kg) of ths anabolic a ndrogenic steroid (AAS), nandrolone decanoate. At the nandrolone dose of 15 mg/kg a significant (about 20-fold) increase in beta-endorphin l evels in the ventral tegmental area (VTA) was observed. The steroid di d not significantly affect the concentration of the peptide at any dos e in other brain areas examined. The levels of MEAP remained unaltered in all studied regions. A slight increase in serum concentrations of both peptides was also found but this elevation was not statistically significant. The observed increase in beta-endorphin in VTA iras sugge sted to be involved in a mechanism by which the steroid may influence the reward system in the brain. An opioid mediated stimulation of the reward system following injection of AAS supports a previous hypothesi s that AAS may induce psychological dependence. (C) 1997 Elsevier Scie nce Ireland Ltd.