Toxic effects of methoxychlor in rat striatum: modifications in several neurotransmitters.
Neurotoxic effects of methoxychlor (MTX) are poorly understood at present. This study was undertaken to evaluate the possible effects of MTX in norepinephrine, dopamine and amino acid contents and serotonin turnover in rat striatum. For this purpose, adult male Sprague-Dawley rats were administered 25 mg/kg/day of MTX in sesame oil or vehicle only for 30 days. The neurotransmitters of interest were measured in the striatum by HPLC. MTX decreased norepinephrine and 5-hydroxyindole acetic acid (5-HIAA) content and serotonin turnover (measured as 5-HIAA/serotonin ratio), and increased glutamate and GABA concentrations. However, the content of serotonin, aspartate, glutamine and taurine was not modified by MTX exposure. These data suggest that MTX exposure inhibits norepinephrine synthesis and serotonin metabolism. The inhibitory effect on norepinephrine could be explained, at least in part, by the increase of both GABA and glutamate contents. Further studies are needed to understand the effects of MTX on serotonin. Also a disruptive effect of MTX on the metabolisms of glutamate, aspartate, glutamine and GABA emerges.
Lafuente
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Laboratorio de Toxicología, Facultad de Ciencias, Universidad de Vigo, Campus de Orense, Las Lagunas, 32004 Ourense, Spain. lafuente@uvigo.es
Cabaleiro
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T
Caride
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Gutiérrez
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Esquifino
A I
AI
D000818:Animals; D001679:Biogenic Amines / Q000378:metabolism*; D003342:Corpus Striatum / Q000187:drug effects*; D004298:Dopamine / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007306:Insecticides / Q000633:toxicity*; D008297:Male; D008731:Methoxychlor / Q000633:toxicity*; D018377:Neurotransmitter Agents / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism
D001679:Biogenic Amines; D007306:Insecticides; D018377:Neurotransmitter Agents; D012701:Serotonin; D018698:Glutamic Acid; D006897:Hydroxyindoleacetic Acid; D005680:gamma-Aminobutyric Acid; D008731:Methoxychlor; D004298:Dopamine; D009638:Norepinephrine