title: 2,3,7,8-Tetrachlorodibenzo-p-dioxin alters steroid secretion but does not affect cell viability and the incidence of apoptosis in porcine luteinised granulosa cells.
abstract: The compound 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), a by-product of human industrial activity, was found to affect ovarian steroidogenesis in animals, but the mechanism of its action is still unclear. The aims of the study were to examine the effect of TCDD on (1) progesterone (P4) and oestradiol (E2) production by granulosa cells isolated from medium (3-6 mm) and preovulatory (≥ 8 mm) porcine follicles, (2) the viability of the cells, and (3) the incidence of apoptosis. Porcine granulosa cells were cultured (48 h) with or without TCDD (100 pM, 100 nM). Steroid hormone concentrations in the medium were determined by radioimmunoassay. The viability of granulosa cells was tested spectrophotometrically (alamarBlue™ assay). Apoptosis was evaluated by flow cytometry using Annexin V and by TUNEL assay. The higher dose of TCDD (100 nM) significantly inhibited P4 and stimulated E2 production by luteinised granulosa cells isolated from medium follicles. The lower dose of TCDD (100 pM) significantly stimulated P4 and inhibited E2 secretion by the cells isolated from preovulatory follicles. None of the two TCDD doses affected cell viability or induced apoptosis in granulosa cells. In conclusion, TCDD directly affected steroid production by granulosa cells obtained from mature pigs, but the effect of TCDD was not due to its cytotoxicity.
authors.affiliation: University of Warmia and Mazury in Olsztyn Department of Zoology Oczapowskiego 1A 10-719 Olsztyn Poland.
authors.forename: Olga
authors.initials: O
authors.lastname: Jablonska
authors.affiliation: University of Warmia and Mazury in Olsztyn Department of Animal Physiology Oczapowskiego 1A 10-719 Olsztyn Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Piasecka-Srader
authors.affiliation: University of Warmia and Mazury in Olsztyn Laboratory of Molecular Diagnostics Oczapowskiego 1A 10-719 Olsztyn Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Nynca
authors.affiliation: University of Warmia and Mazury in Olsztyn Department of Animal Physiology Oczapowskiego 1A 10-719 Olsztyn Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Kołomycka
authors.affiliation: University of Warmia and Mazury in Olsztyn Department of Comparative Anatomy Oczapowskiego 1A 10-719 Olsztyn Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Robak
authors.affiliation: Polish Academy of Sciences Institute of Animal Reproduction and Food Research Olsztyn Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Wąsowska
authors.affiliation: University of Warmia and Mazury in Olsztyn Department of Animal Physiology Oczapowskiego 1A 10-719 Olsztyn Poland University of Warmia and Mazury in Olsztyn Laboratory of Molecular Diagnostics Oczapowskiego 1A 10-719 Olsztyn Poland.
authors.forename: Renata E
authors.initials: RE
authors.lastname: Ciereszko
keywords: TCDD; TUNEL; annexin V; apoptosis; flow cytometry; granulosa cells; pig; steroid secretion