Is the natural PCDD/PCDF mixture toxic for human placental JEG-3 cell line? The action of the toxicants on hormonal profile, CYP1A1 activity, DNA damage and cell apoptosis.

The present study was conducted to define the action of a mixture obtained by the extraction and purification of real fly ash, on specific toxicity endpoints, such as hormonal secretion, CYP1A1 expression, DNA damage and cell apoptosis. JEG-3 cell line was exposed in vitro to different doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or Polychlorinated dibenzo-p-dioxin/Polychlorinated dibenzo-P-furan (PCDD/PCDF) mixture. Both TCDD and the mixture decreased hCG secretion, while inhibition of progesterone levels was noted only under the influence of TCDD.

The short- and long-term effects of two isomers of DDT and their metabolite DDE on hormone secretion and survival of human choriocarcinoma JEG-3 cells.

JEG-3 cells were used to compare the effects of two isomers of DDT (1,1,1,-trichloro-2,2-bis(p-chlorophenyl)ethane), p,p'-DDT and o,p'-DDT and their metabolite DDE (1,1,-dichloro-2,2-bis(p-chlorophenyl)ethylene) on progesterone (P4) and human chorionic gonadotropin (hCG) secretion and cell apoptosis. Cells were treated with 1, 10, 100 ng/ml or 1 mug/ml of each compound for 24 or 72 h. Twenty four hours of exposure at 1 mug/ml of p,p'-DDT and o,p'-DDT decreased, whereas both DDEs, at all investigated concentrations, increased P4 secretion.

Expression of atrial natriuretic peptide, progesterone, apoptosis-related proteins and caspase-3 in in vitro luteinized and leptin-treated porcine granulosa cells.

Objective: Our aim was to examine the expression patterns of ANP, the rate of apoptosis bcl-2 and p53 expression and caspase-3 activity and progesterone (P) production in porcine granulosa cells (pGCs) stimulated in vitro for luteinization and after treatment with leptin.

Methods: Freshly isolated prepubertal pGCs were cultured as monolayers for 24 h, subsequently FSH was supplemented for 24 h, and finally LH was added to a part of the cells for 24 h to induce luteinization. The effect of leptin on in vitro luteinized pGCs was tested by the addition of 10 ng/ml human recombinant leptin (hrL) 24 h after LH administration.

Lack of synergy between estrogen and progesterone on local IGF-I, IGFBP-3 and IGFBP-2 secretion by both hormone-dependent and hormone-independent breast cancer explants in vitro. Effect of tamoxifen and mifepristone (RU 486).

The aim of the present study was to investigate direct effects of estrogen (E2) or progesterone (P4) given separately vs. estrogen+progesterone on local IGF-I, IGFBP-3 and IGFBP-2 secretion. Explants obtained from estrogen receptor positive plus progesterone receptor positive (ER+/PR+) and hormone receptors negative (ER-/PR-) tumors were incubated with E2, P4 or both.

The impact of progesterone on simultaneous, local secretion of IGFBP-3 and IGF-I [IGFBP-3/IGF-I index] by human malignant and non-malignant breast explants depends on tissue steroid receptor phenotype.

Objectives: Insulin-like growth factor-I (IGF-I) is regarded as one of mammary tissue proliferative factors. Insulin-like growth factor binding protein-3 (IGFBP-3) limits the IGF-I binding potential to its receptor. That limits the IGF-I bioavailability.

Localization of atrial natriuretic peptide in pig granulosa cells isolated from ovarian follicles of various size.

The aim of the current study was to present the spatial distribution of atrial natriuretic peptide (ANP) in short-term cultures of pig granulosa cells obtained from small, medium, and large ovarian follicles. The specific immunoreactivity was detected by three monoclonal antibodies recognizing different epitopes of the ANP molecule (Mab 6C3, Mab 6F11, Mab5D3). The specific ANP immunoreactivity detected by Mab 6C3 and Mab 6F11 showed dense staining of cytoplasm and was similar in granulosa cells from small and medium follicles.

Effects of dioxin (2,3,7,8-TCDD) and PCDDs/PCDFs congeners mixture on steroidogenesis in human placenta tissue culture.

Objective: The aim was to compare the direct effect of most toxic 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) as well as of naturally occurring congener mixture of polychlorinated dibenzodioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) extracted from fly ash on the placental steroidogenesis. The concentration of all 17 toxic congeners was reported and the toxic equivalent (TEQ) was calculated as a 27.7 micrograms-TEQ/kg of fly ash.