Reduced activity of monoamine oxidase in the rat brain following repeated nandrolone decanoate administration.
Anabolic androgenic steroids (AAS) are known as doping agents within sports and body-building, but are currently also abused by other groups in society in order to promote increased courage and aggression. We previously showed that 14 days of daily intramuscular injections of the AAS nandrolone decanoate (15 mg/kg) reduced the extracellular levels of the dopaminergic metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the nucleus accumbens shell using microdialysis. The aim of the present study was to investigate whether the same dose regimen of nandrolone decanoate may affect the activities of the dopamine-metabolizing enzymes monoamine oxidases A and B (MAO-A and MAO-B). A radiometric assay was used to determine the activities of MAO-A and MAO-B in rat brain tissues after 14 days of daily i.m. nandrolone decanoate injections at the doses 3 and 15 mg/kg. Gene transcript contents of MAO-A, MAO-B and cathecol-O-methyltransferase (COMT) were measured with quantitative real-time reverse transcription PCR. 3 mg/kg of nandrolone decanoate significantly reduced the activity of both MAO-A and -B in the caudate putamen. 15 mg/kg of nandrolone decanoate significantly reduced the activity of MAO-A in the amygdala and increased the gene transcript level of MAO-B in the substantia nigra. In conclusion, imbalanced MAO activities may contribute to explain the impulsive and aggressive behaviour often described in AAS abusers. The reduced MAO activities observed are in line with our previously presented findings of decreased extracellular levels of DOPAC and HVA in the rat brain, indicating decreased monoaminergic activity following repeated AAS administration.
Department of Pharmaceutical Biosciences, Division of Pharmaceutical Pharmacology, Uppsala University, Box 591 Biomedical Centre, SE-751 24 Uppsala, Sweden. carolina.birgner@farmbio.uu.se
Carolina
C
Birgner
Anna M S
AM
Kindlundh-Högberg
Lars
L
Oreland
Johan
J
Alsiö
Jonas
J
Lindblom
Helgi B
HB
Schiöth
Lena
L
Bergström
D045930:Anabolic Agents / Q000008:administration & dosage*; D000704:Analysis of Variance; D000818:Animals; D001921:Brain / Q000187:drug effects* / Q000201:enzymology; D004334:Drug Administration Schedule; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D008297:Male; D008995:Monoamine Oxidase / Q000235:genetics / Q000378:metabolism*; D009277:Nandrolone / Q000008:administration & dosage / Q000031:analogs & derivatives*; D000077603:Nandrolone Decanoate; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley
D045930:Anabolic Agents; D012333:RNA, Messenger; D009277:Nandrolone; D008995:Monoamine Oxidase; D000077603:Nandrolone Decanoate