Effect of repeated dietary exposure of aflatoxin B1 on brain biogenic amines and metabolites in the rat.
Male Sprague-Dawley rats were treated po twice weekly for 3 weeks with a low (32.8 micrograms/kg) and high dose (327.9 micrograms/kg) of aflatoxin B1 (AFB1) in corn oil. A control group received corn oil only. At the end of the experiment the rats were killed, and the concentrations of the brain catecholamines, norepinephrine (NE) and dopamine (DA), catecholamine metabolites, 3-methoxy-4-hydroxymandelic acid (VMA), homovanillic acid (HVA), and dihydroxyphenylacetic acid (DOPAC), and the indoleamine serotonin (5-HT) and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), were determined by high-pressure liquid chromatography in five brain regions. The major effects were found in striatal dopamine and serotonin concentrations, with decreases of 37 and 29%, respectively. A corresponding decline was observed in the dopamine metabolites, homovanillic acid (44%) and dihydroxyphenylacetic acid (30%). Concentrations of these neurotransmitters and metabolites were only marginally altered in cerebral cortex, cerebellum, hypothalamus, and medulla oblongata. It appears that a major effect of AFB1 is on dopaminergic pathways, possible by selectively perturbing the conversion of tyrosine to biogenic catecholamine neurotransmitters.
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D015102:3,4-Dihydroxyphenylacetic Acid / Q000378:metabolism; D016604:Aflatoxin B1; D000348:Aflatoxins / Q000494:pharmacology*; D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism*; D001835:Body Weight; D001921:Brain / Q000187:drug effects* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D004032:Diet; D004298:Dopamine / Q000378:metabolism; D006719:Homovanillic Acid / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D008297:Male; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000378:metabolism; D014642:Vanilmandelic Acid / Q000378:metabolism
D000348:Aflatoxins; D001679:Biogenic Amines; D015102:3,4-Dihydroxyphenylacetic Acid; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D014642:Vanilmandelic Acid; D016604:Aflatoxin B1; D004298:Dopamine; D009638:Norepinephrine; D006719:Homovanillic Acid