Melatonin prevents damage elicited by the organophosphorous pesticide diazinon on the mouse testis.
Organophosphates like O,O-diethyl O-2-isopropyl-6-methyl pyrimidinyl-4-g-1-phosphorothioate (diazinon) are pesticides used worldwide, which can affect both animals and man even after a single exposure. Whereas their toxicity is due to acetylcholinesterase inhibition, their secondary toxic effects have been related to free oxygen radicals. This study evaluates the effects of a single dose of diazinon and melatonin-a powerful antioxidant-on plasmatic acetylcholinesterase activity and testis histopathology in adult mice 1 and 32 days post-treatment. Diazinon diminished the plasma acetylcholinesterase activity on day 1 post-treatment, although testosterone levels remained unaffected. Morphometrical analysis showed a decrease in seminiferous epithelium height (days 1 and 32), whereas an increase in testicular superoxide dismutase (SOD) activity was detected (day 32). Melatonin pretreatment prevented every alteration induced by diazinon, except the diminution of acetylcholinesterase plasmatic activity. Testicular damage might be due to elevated concentrations of free oxygen radicals released upon diazinon exposure, inducing alterations in the DNA and promoting local apoptosis; however, antioxidant pretreatment with melatonin prevents or diminishes this damage.
Anatomy and Developmental Biology Program, School of Medicine, University of Chile, Independencia 1027, Santiago, Metropolitana, Chile.
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Sarabia
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Maurer
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Bustos-Obregón
D000110:Acetylcholinesterase / Q000097:blood; D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002800:Cholinesterase Inhibitors / Q000633:toxicity*; D002802:Cholinesterases / Q000097:blood / Q000187:drug effects; D003976:Diazinon / Q000633:toxicity*; D004336:Drug Antagonism; D007306:Insecticides / Q000633:toxicity*; D008297:Male; D008550:Melatonin / Q000494:pharmacology*; D051379:Mice; D018384:Oxidative Stress / Q000187:drug effects; D012670:Seminiferous Epithelium / Q000187:drug effects / Q000473:pathology; D013482:Superoxide Dismutase / Q000378:metabolism; D013733:Testicular Diseases / Q000139:chemically induced / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D013737:Testis / Q000187:drug effects* / Q000201:enzymology / Q000473:pathology; D013739:Testosterone / Q000097:blood
D000975:Antioxidants; D002800:Cholinesterase Inhibitors; D007306:Insecticides; D013739:Testosterone; D013482:Superoxide Dismutase; D000110:Acetylcholinesterase; D002802:Cholinesterases; D008550:Melatonin; D003976:Diazinon