Effect of Repeated Dietary Exposure of Aflatoxin B1 on Brain Biogenic Amines and Metabolites in the Rat
Toxicology and Applied Pharmacology
Male Sprague-Dawley rats were treated po twice weekly for 3 weeks with a low (32.8 μg/kg) and high dose (327.9 μg/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.
Coulombe, R.A. and R.P. Sharma (1985). Effect of repeated dietary exposure of aflatoxin B1 on brain biogenic amines amines and metabolites in rats. Toxicol. Appl. Pharmacol. 80:496-501.