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Keywords:

  • Rat brain;
  • dopamine;
  • 5-hydroxytryptamine;
  • anabolic androgenic steroids;
  • frontal cortex;
  • striatum;
  • hippocampus;
  • hypothalamus
  • The effects of treating groups of rats with four different anabolic androgenic steroids (AAS) (testosterone, nandrolone, methandrostenolone, and oxymetholone) on 5-hydroxytryptamine (5-HT) and dopamine (DA) neurones in different brain regions were examined. The AAS was injected six times with 1 week's interval and the rats were sacrificed 2 days after the final injection. 5-HT and its metabolite 5-hydroxyindoleacetic acid (5-HIAA), DA and its metabolites 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were measured. The effect on DA and 5-HT synthesis rate was analysed as the accumulation of 3,4-dihydroxyphenyl-alanine (DOPA) and 5-hydroxytryptophan (5-HTP), respectively, after inhibition of the amino acid decarboxylase with NSD-1015 (3-hydroxy-benzylhydrazine dihydrochloride). Additionally, the monoamine oxidase (MAO) activity was analysed in the hypothalamus.

  • The DOPAC+HVA/DA ratio was increased in the striatum in all treatment groups. However, the synthesis rate of DA was significantly increased only in the methandrostenolone treated group.

  • The 5-HIAA/5-HT ratio was increased in all treatment groups in the hippocampus, in the frontal cortex in the methandrostenolone-treated animals and in the hypothalamus in the testosterone- and oxymetholone-treated rats, while the 5-HT synthesis rate was not affected by the AAS-treatments.

  • The MAO-A activity was increased in the oxymetholone-treated rats while the other treatment groups were unaffected. The MAO-B activity was not changed.

  • The results indicate that relatively high doses of AAS increase dopaminergic and 5-hydroxytryptaminergic metabolism in male rat brain, probably due to enhanced turnover in these monaminergic systems.

British Journal of Pharmacology (1999) 126, 1301–1306; doi:10.1038/sj.bjp.0702412