title: Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin and phytoestrogen genistein on the activity and the presence of steroidogenic enzyme proteins in cultured granulosa cells of pigs.
abstract: Environmental estrogens such as dioxins (e.g. 2,3,7,8-tetrachlorodibenzo-p-dioxin; TCDD) and phytoestrogens (e.g. genistein; G) are known to influence endocrine and reproductive processes in humans and animals. Because living organisms are usually exposed to small, non toxic, doses of dioxins and phytoestrogens, the aims of the study were to determine the effects of small, environmentally relevant doses of TCDD (100pM) and/or genistein (500nM) on: (1) the activity of steroidogenic enzymes (cholesterol side-chain cleavage enzyme, P450scc; 3β-hydroxysteroid dehydrogenase, 3β-HSD and aromatase, P450arom) and (2) amount of protein of the enzymes in granulosa cells isolated from medium and large ovarian follicles of pigs. To determine the activity of the enzymes, the incubation medium was supplemented with specific steroid substrates (25-hydroxycholesterol; pregnenolone; testosterone) of particular steroidogenic enzymes (P450scc, 3β-HSD and P450arom, respectively). Subsequently, the production of progesterone (P450scc and 3β-HSD) or estradiol (P450arom) was compared in the presence and absence of the appropriate steroid precursor. Neither genistein nor genistein combined with TCDD affected activity of P450arom and relative amounts of steroidogenic enzyme proteins in the examined granulosa cells of pigs. In contrast, genistein alone and in combination with TCDD decreased P450scc and 3β-HSD activity as well as progesterone production in granulosa cells isolated from medium and large follicles of pigs. Because TCDD alone did not affect steroid hormone production or enzyme activity, the above effects should be ascribed solely to genistein. It appears that the effects of the examined doses of TCDD and genistein on granulosal cell functions were not additive.
authors.affiliation: Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719 Olsztyn, Poland. Electronic address: jpiasecka-Srader@kumc.edu.
authors.forename: Joanna
authors.initials: J
authors.lastname: Piasecka-Srader
authors.affiliation: Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719 Olsztyn, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kolomycka
authors.affiliation: Research and Educational Center, Laboratory of Molecular Diagnostics, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Nynca
authors.affiliation: Department of Animal Physiology, University of Warmia and Mazury in Olsztyn, Oczapowskiego 1A, 10-719 Olsztyn, Poland; Research and Educational Center, Laboratory of Molecular Diagnostics, University of Warmia and Mazury in Olsztyn, Olsztyn, Poland. Electronic address: reniac@uwm.edu.pl.
authors.forename: Renata E
authors.initials: RE
authors.lastname: Ciereszko
mesh_terms: D015067:17-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000818:Animals; D001141:Aromatase / Q000378:metabolism*; D002478:Cells, Cultured; D002786:Cholesterol Side-Chain Cleavage Enzyme / Q000378:metabolism*; D004785:Environmental Pollutants / Q000494:pharmacology; D005260:Female; D019833:Genistein / Q000494:pharmacology*; D006107:Granulosa Cells / Q000187:drug effects* / Q000201:enzymology / Q000378:metabolism; D048789:Phytoestrogens / Q000494:pharmacology; D000072317:Polychlorinated Dibenzodioxins / Q000494:pharmacology*; D011374:Progesterone / Q000378:metabolism; D013552:Swine
chemical_list: D004785:Environmental Pollutants; D048789:Phytoestrogens; D000072317:Polychlorinated Dibenzodioxins; D011374:Progesterone; D019833:Genistein; D015067:17-Hydroxysteroid Dehydrogenases; C044256:3 (or 17)-beta-hydroxysteroid dehydrogenase; D001141:Aromatase; D002786:Cholesterol Side-Chain Cleavage Enzyme
keywords: 3β-HSD; P450arom; P450scc; Pig; Steroidogenesis; Xenoestrogens