Endosulfan effects on pituitary hormone and both nitrosative and oxidative stress in pubertal male rats.
The present study was undertaken to investigate in pubertal male rats possible effects of endosulfan administered throughout lactation and gestation on: (a) pituitary gene expression of prolactin, luteinizing hormone (LH), growth hormone (GH) and thyroid stimulating hormone (TSH); (b) circulating levels of these hormones; and (c) expression of nitric oxide synthase 1 and 2 (NOS1 and NOS2), and heme oxygenase-1 (HO-1) at pituitary level. Endosulfan was administered orally at the doses of 0.61 mg/kg/day or 6.12 mg/kg/day, and possible toxic effects were studied in pubertal male pups (at postnatal day 30). Gene expression was evaluated by RT-PCR and plasma hormone levels by RIA. Exposure to both administered doses down-regulated LH, GH and TSH. Treatment with 0.61 mg endosulfan/kg/day decreased prolactin expression, although its plasmatic concentration was decreased by both administered doses. LH secretion was stimulated by both doses, whereas the highest dose increased GH levels and decreased plasma TSH concentration. Endosulfan up-regulated NOS1 and NOS2. We can conclude that in pubertal male rat, prenatal and lactational exposure to endosulfan modifies expression and release of prolactin, LH, GH and TSH, and pituitary NOS1 and NOS2 mRNA levels, suggesting that nitrosative stress can be implicated in the endocrine toxicity of endosulfan at pituitary level.
Caride
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Laboratorio de Toxicología, Facultad de Ciencias, Universidad de Vigo, Campus de Orense, Las Lagunas, 32004 Orense, Spain.
Lafuente
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Cabaleiro
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D000818:Animals; D004305:Dose-Response Relationship, Drug; D004726:Endosulfan / Q000494:pharmacology / Q000633:toxicity*; D005260:Female; D005786:Gene Expression Regulation / Q000187:drug effects*; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism; D007306:Insecticides / Q000494:pharmacology / Q000633:toxicity*; D007774:Lactation; D008297:Male; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D015538:Nitrosation / Q000187:drug effects; D018384:Oxidative Stress / Q000187:drug effects; D010907:Pituitary Hormones / Q000378:metabolism*; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D012741:Sexual Maturation; D013312:Stress, Physiological / Q000187:drug effects*
D007306:Insecticides; D010907:Pituitary Hormones; D012333:RNA, Messenger; D019001:Nitric Oxide Synthase; D051547:Heme Oxygenase-1; D004726:Endosulfan