title: Short-term hormone release from adult female rat hypothalamic and pituitary explants is not altered by 2,3,7,8-tetrachlorodibenzo-p-dioxin.
abstract: 2, 3, 7,8-Tetrachlorodibenzo-p-dioxin (TCDD) has adverse effects on reproduction, in part due to direct actions at the ovary. It is unclear whether effects are further mediated by glands that regulate ovarian function. We investigated whether effects of TCDD are mediated via the hypothalamic-pituitary axis. Hypothalamic and pituitary tissues were cultured in medium with and without TCDD. TCDD did not alter GnRH release from hypothalamic samples. It continued to be pulsatile with no differences in the average peak frequency, average peak amplitude, or baseline GnRH release. TCDD did not alter GnRH-induced release of gonadotropins from pituitary samples. There were no differences in average peak amplitude or baseline release. AhR, ARNT or ER alpha mRNA copy numbers in cultured pituitaries were not affected by TCDD. Our data suggest that TCDD effects on ovarian function are not mediated through the hypothalamic or pituitary release parameters tested in this study.
authors.affiliation: Department of Biology, University of Wisconsin-Platteville, Platteville, Wisconsin 53818, USA.
authors.forename: Amanda Louise
authors.initials: AL
authors.lastname: Trewin
authors.forename: Michael John
authors.initials: MJ
authors.lastname: Woller
authors.forename: Barbara Ann Brown
authors.initials: BA
authors.lastname: Wimpee
authors.forename: Lisa Kay
authors.initials: LK
authors.lastname: Conley
authors.forename: Monika Gabriella
authors.initials: MG
authors.lastname: Baldridge
authors.forename: Reinhold J
authors.initials: RJ
authors.lastname: Hutz
mesh_terms: D000818:Animals; D004785:Environmental Pollutants / Q000494:pharmacology*; D004958:Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000378:metabolism; D007987:Gonadotropin-Releasing Hormone / Q000378:metabolism; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism*; D007986:Luteinizing Hormone / Q000378:metabolism; D008686:Metestrus; D009924:Organ Culture Techniques; D010902:Pituitary Gland / Q000187:drug effects* / Q000378:metabolism*; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D011359:Proestrus; D011374:Progesterone / Q000097:blood; D011673:Pulsatile Flow; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone