title: Effect of PCB 126 on aryl hydrocarbon receptor 1 (AHR1) and AHR1 nuclear translocator 1 (ARNT1) mRNA expression and CYP1 monooxygenase activity in chicken (Gallus domesticus) ovarian follicles.
abstract: The aim of the experiment was to study the in vitro effect of 3,3',4,4',5-pentachlorobiphenyl (PCB 126; a coplanar PCB congener) on aryl hydrocarbon receptor (AHR1) and AHR1 nuclear translocator (ARNT1) mRNA expression and the activity of CYP1 family monooxygenases in chicken ovarian follicles. White (1-4 mm) and yellowish (4-8 mm) prehierarchical follicles as well as fragments of the theca and granulosa layers of the 3 largest preovulatory follicles (F3-F1) were incubated in a medium supplemented with 0 (control group), 1, 10 or 100 nM PCB 126. The incubation was carried out for 6 h or 24 h for determination of mRNA expression of AHR1 and ARNT1 genes (real-time qPCR) and CYP1 monooxygenase activity (EROD and MROD fluorometric assays), respectively. It was found that chicken ovarian follicles express mRNA of AHR1 and ARNT1 genes. A modulatory effect of PCB 126 on AHR1 and ARNT1 expression depended not only on the biphenyl concentration but also on the follicular layer and the maturational state of the follicle. EROD and MROD activities appeared predominantly in the granulosa layer of the yellow preovulatory follicles. PCB 126 induced these activities in a dose-dependent manner in all ovarian follicles. The obtained results suggest that ovarian follicles, especially the granulosa layer, are involved in the detoxification process of PCBs in the laying hen. Taking this finding into consideration it can be suggested that the granulosa layer of the yellow hierarchical follicles plays a key role in the protective mechanism which reduces the amount of transferred dioxin-like compounds into the yolk of the oocyte.
authors.affiliation: Department of Physiology, Jagiellonian University Medical College, Cracow, Poland.
authors.forename: Dagmara
authors.initials: D
authors.lastname: Wójcik
authors.affiliation: Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Al. Mickiewicza 24/28, 30-059 Krakow, Poland.
authors.forename: Piotr A
authors.initials: PA
authors.lastname: Antos
authors.affiliation: Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Al. Mickiewicza 24/28, 30-059 Krakow, Poland.
authors.forename: Dorota
authors.initials: D
authors.lastname: Katarzyńska
authors.affiliation: Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Al. Mickiewicza 24/28, 30-059 Krakow, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Hrabia
authors.affiliation: Department of Animal Physiology and Endocrinology, University of Agriculture in Krakow, Al. Mickiewicza 24/28, 30-059 Krakow, Poland. Electronic address: rzsechma@cyf-kr.edu.pl.
authors.forename: Andrzej
authors.initials: A
authors.lastname: Sechman
mesh_terms: D000818:Animals; D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics / Q000378:metabolism*; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator / Q000235:genetics / Q000378:metabolism*; D002645:Chickens; D005260:Female; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects*; D006080:Ovarian Follicle / Q000187:drug effects* / Q000201:enzymology; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018336:Receptors, Aryl Hydrocarbon / Q000235:genetics / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D018336:Receptors, Aryl Hydrocarbon; D051784:Aryl Hydrocarbon Receptor Nuclear Translocator; D011078:Polychlorinated Biphenyls; D001189:Aryl Hydrocarbon Hydroxylases; C023035:3,4,5,3',4'-pentachlorobiphenyl
keywords: AHR1; ARNT1; Chicken; EROD; MROD; Ovary; PCB 126