Effects of oral administration of chlordecone and mirex on brain biogenic amines in mice

Levels of norepinephrine (NE), dopamine (DA), serotonin (5-HT) and the 5-HT metabolite, 5-hydroxyindole acetic acid (5-HIAA) were determined in brains of mice after daily oral administration of 10, 25 or 50 mg/kg of chlordecone or mirex until mortality occurred. Significant decreases in whole brain and striatal DA levels were observed in chlordecone-treated mice exhibiting tremors. Mirex had no effect at the 3 doses tested. In mice treated with chlordecone or mirex, the 5-HT levels were elevated only in animals exhibiting severe tremors or diarrhea, respectively. NE levels were not altered by chlordecone or mirex. These results suggest that chlordecone-induced neurotoxicity may be due in part to a decrease in the inhibitory state of dopamine neurons.