Short-term hormone release from adult female rat hypothalamic and pituitary explants is not altered by 2,3,7,8-tetrachlorodibenzo-p-dioxin.
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.
Trewin
Amanda Louise
AL
Department of Biology, University of Wisconsin-Platteville, Platteville, Wisconsin 53818, USA.
Woller
Michael John
MJ
Wimpee
Barbara Ann Brown
BA
Conley
Lisa Kay
LK
Baldridge
Monika Gabriella
MG
Hutz
Reinhold J
RJ
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
D004785:Environmental Pollutants; D000072317:Polychlorinated Dibenzodioxins; D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone