Effects of drug-induced changes in brain monoamines on aggression and motor behavior in mice.
Mice maintained on a basal casein diet supplemented with 4% L-tyrosine potentiated L-DOPA effects on aggression. At low doses (12.5-25 mg/kg) L-DOPA increased aggression whereas at high doses (50-100 mg/kg) it decreased aggression. 5-HTP (50-200 mg/kg) produced a dose-dependent decrease in aggression and motor activity which was antagonized by pretreatment with dietary L-tyrosine (4%) or L-DOPA (50 mg/kg). L-DOPA induced reductions in motor activity were, in turn, antagonized by 5-HTP. Increases in motor activity following d-amphetamine (3 mg/kg) were sharply reduced by 5-HTP (50-100 mg/kg), but 5-HTP potentiated reductions in aggression following d-amphetamine. The concentration in brain of tyrosine, DOPA, dopamine (DA), noradrenaline (NA), DOPAC, HVA, tryptophan, serotonin (5-HT), and 5-HIAA were obtained following drug and diet treatments. The changes observed, particularly in DA and 5-HT metabolites, provide further evidence for an inhibitory role of brain 5-HT systems in the mediation of the behavioral effects of d-amphetamine and the catecholamine precursors, L-tyrosine and L-DOPA.
D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D006916:5-Hydroxytryptophan / Q000494:pharmacology; D000374:Aggression / Q000187:drug effects*; D000661:Amphetamine / Q000494:pharmacology; D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism*; D001923:Brain Chemistry / Q000187:drug effects*; D004032:Diet; D004305:Dose-Response Relationship, Drug; D006719:Homovanillic Acid / Q000378:metabolism; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007980:Levodopa / Q000494:pharmacology; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D014443:Tyrosine / Q000378:metabolism / Q000494:pharmacology
D001679:Biogenic Amines; D015102:3,4-Dihydroxyphenylacetic Acid; D014443:Tyrosine; D007980:Levodopa; D006897:Hydroxyindoleacetic Acid; D006916:5-Hydroxytryptophan; D000661:Amphetamine; D006719:Homovanillic Acid