title: Atrazine blocks ovulation via suppression of Lhr and Cyp19a1 mRNA and estradiol secretion in immature gonadotropin-treated rats.
abstract: We investigated whether in vivo exposure to herbicide atrazine (ATR) exerts anovulatory effect by direct action in the ovary. Female rats were given ATR (50mg/kg body weight) during equine chorionic gonadotropin (eCG) priming. Forty eight hours after eCG administration, the animals were injected with human CG (hCG) to induce ovulation. ATR blocked ovulation and prevented expression of epiregulin and progesterone receptor mRNA in hCG-treated animals. During eCG-induced follicular growth, ATR suppressed luteinizing hormone receptor (Lhr) and aromatase expression in granulosa cells and decreased estradiol (E2) serum levels. ATR increased cytochrome p450 1b1 (Cyp1b1) mRNA expression after both in vivo and in vitro exposures. In vitro addition of beta-naphthoflavone, a known Cyp1b1 mRNA inductor, suppressed follicle-stimulating hormone-induced Lhr expression. Collectively, these data indicate that under in vivo conditions, ATR may act directly on granulosa cells by decreasing E2 levels and Lhr mRNA, thus leading to inhibition of ovulation.
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Laboratory for Ecotoxicology, Novi Sad, Serbia.
authors.forename: Dragana
authors.initials: D
authors.lastname: Samardzija
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Laboratory for Ecotoxicology, Novi Sad, Serbia.
authors.forename: Kristina
authors.initials: K
authors.lastname: Pogrmic-Majkic
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Laboratory for Ecotoxicology, Novi Sad, Serbia.
authors.forename: Svetlana
authors.initials: S
authors.lastname: Fa
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Laboratory for Ecotoxicology, Novi Sad, Serbia.
authors.forename: Branka
authors.initials: B
authors.lastname: Glisic
authors.affiliation: University of Novi Sad, Faculty of Technical Sciences, Department of Environmental Engineering and Occupational Safety and Health, Novi Sad, Serbia.
authors.forename: Bojana
authors.initials: B
authors.lastname: Stanic
authors.affiliation: University of Novi Sad, Faculty of Sciences, Department of Biology and Ecology, Laboratory for Ecotoxicology, Novi Sad, Serbia. Electronic address: nebojsa.andric@dbe.uns.ac.rs.
authors.forename: Nebojsa
authors.initials: N
authors.lastname: Andric
mesh_terms: D000818:Animals; D001141:Aromatase / Q000235:genetics*; D001280:Atrazine / Q000633:toxicity*; D002478:Cells, Cultured; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000235:genetics; D056742:Cyclin D2 / Q000235:genetics; D065633:Cytochrome P-450 CYP1B1 / Q000235:genetics; D066260:Epiregulin / Q000235:genetics; D004958:Estradiol / Q000097:blood*; D005260:Female; D006064:Gonadotropins, Equine / Q000494:pharmacology; D006107:Granulosa Cells / Q000187:drug effects / Q000378:metabolism; D006540:Herbicides / Q000633:toxicity*; D010060:Ovulation / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D017208:Rats, Wistar; D011974:Receptors, LH / Q000235:genetics*; D011980:Receptors, Progesterone / Q000235:genetics
chemical_list: C486197:Ccnd2 protein, rat; D056742:Cyclin D2; D066260:Epiregulin; C587882:Ereg protein, rat; D006064:Gonadotropins, Equine; D006540:Herbicides; D012333:RNA, Messenger; D011974:Receptors, LH; D011980:Receptors, Progesterone; D004958:Estradiol; D001141:Aromatase; C585499:Cyp1b1 protein, rat; D065633:Cytochrome P-450 CYP1B1; D002786:Cholesterol Side-Chain Cleavage Enzyme; D001280:Atrazine
keywords: Ahr; Atrazine; Cyp19a1; Cyp1b1; Lhr; Ovulation