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DrożakPaulina, Duda Piotr, Augustowska Katarzyna, Drożak Martyna,Bryliński Łukasz, Bura Agata, Rudnicka-Drożak Ewa. Adverse Childhood Experiences and worsened social relationships in adult life among Polish medical and dental students. Journal of Education, Health and Sport. 2021;11(8):119-133. eISSN 2391-8306. DOI http://dx.doi.org/10.12775/JEHS.2021.11.08.013 https://apcz.umk.pl/czasopisma/index.php/JEHS/article/view/JEHS.2021.11.08.013 https://zenodo.org/record/5201522 The journal has had 5 points in Ministry of Science and Higher Education parametric evaluation. § 8. 2) and § 12. 1. 2) 22.02.2019. © The Authors 2021; This article is published with open access at Licensee Open Journal Systems of Nicolaus Copernicus University in Torun, Poland Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author (s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non commercial license Share alike. (http://creativecommons.org/licenses/by-nc-sa/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. The authors declare that there is no conflict of interests regarding the publication of this paper. Received: 01.08.2021. Revised: 10.08.2021. Accepted: 14.08.2021. Adverse Childhood Experiences and worsened social relationships in adult life among Polish medical and dental students Paulina Drożak1, Piotr Duda1, Katarzyna Augustowska1, Martyna Drożak1, ŁukaszBryliński1, Agata Bura1, Ewa Rudnicka-Drożak2 Students’ Scientific Association of Chair and Department of Family Medicine, Medical University of Lublin. Chair and Department of Family Medicine, Medical University of Lublin. Abstract Introduction and purpose. Adverse Childhood Experiences (ACEs) are potentially traumatic events experienced before the age of 18 that have lasting negative effects on physical and mental health. Numerous studies have shown that exposure to Adverse Childhood Experiences increases the probability of chronic health conditions, such as obesity, diabetes, coronary heart disease, asthma, depression or PTSD. The aim of the study was to investigate the prevalence of Adverse Childhood Experiences among medical and dental students of Polish Medical Universities and to examine an association between ACEs and chosen factors associated with social relationships of the students. Material and method. A total of 1162 medical and dental students from each year of education and 18 different Polish universities took part in the study. The research tool contained the Adverse Childhood Experiences standardized questionnaire and authors’ questions. Results. More than a half of the students (57.4%) had at least 1 exposure to ACEs. 8.43% of them experienced 4 or more childhood adversities. The most commonly reported ACEs were: emotional neglect (23.06%), emotional abuse (22.98%) and mental illness or a suicide attempt in a household member (21.86%). An overall graded relationship was found between ACE score and: parents’ lower level of education, negative relationship with parents, siblings and friends and having a diagnosis of depression. Conclusions. Adverse Childhood Experiences are common among Polish medical and dental students and are associated with worsened social relationships and depression in adult life of the students. It is important to implement strategies that aim to prevent ACEs and help to build social support networks for those that are affected by them. Key words: Adverse Childhood Experiences; medical students; dental students.

DrożakPaulina,DudaPiotr,BrylińskiŁukasz,AugustowskaKatarzyna,DrożakMartyna,BuraAgata,Rudnicka-DrożakEwa.Depression among Polish medical students and its lifestyle-linked predictors. Journal of Education, Health and Sport. 2021;11(7):156-166. eISSN 2391-8306. DOI http://dx.doi.org/10.12775/JEHS.2021.11.07.014 https://apcz.umk.pl/czasopisma/index.php/JEHS/article/view/JEHS.2021.11.07.014 https://zenodo.org/record/5122914 The journal has had 5 points in Ministry of Science and Higher Education parametric evaluation. § 8. 2) and § 12. 1. 2) 22.02.2019. © The Authors 2021; This article is published with open access at Licensee Open Journal Systems of Nicolaus Copernicus University in Torun, Poland Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author (s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non commercial license Share alike. (http://creativecommons.org/licenses/by-nc-sa/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. The authors declare that there is no conflict of interests regarding the publication of this paper. Received: 12.07.2021. Revised: 20.07.2021. Accepted: 22.07.2021. Depression among Polish medical students and its lifestyle-linked predictors Paulina Drożak1, Piotr Duda1, Łukasz Bryliński1, Katarzyna Augustowska1, Martyna Drożak1, Agata Bura1, Ewa Rudnicka-Drożak2 Students’ Scientific Association of Chair and Department of Family Medicine, Medical University of Lublin. Chair and Department of Family Medicine, Medical University of Lublin. Abstract Introduction and objective. Depression is a common mental disorder that affects over 264 million people worldwide. Medical students are at a particularly high risk of this disease. The aim of the study was to investigate the prevalence of depression among Polish medical students and to determine predictors of this disease that are related to student’s lifestyle.Material and method.A total of 1023 medical students took part in the study. The research tool included a Polish version of the PHQ-9 questionnaire and author’s questions which concerned sociodemographic characteristics of the investigated group and analyzed factors. Answers were collected in the April of 2020. Results.About a half of the students (51.61%, 95% CI: 48.50 – 54.72) were found to have major depression (PHQ score ≥ 10). 30.21% of the students had mild depressive symptoms, 26.00% – moderate depressive symptoms and 15.05% – moderately severe depressive symptoms. 10.56% of the participants had symptoms of severe depression. A statistically significant relationship was found between major depression and: frequent feelings of loneliness, not doing sports regularly, not getting enough sleep, not participating in social meetings often enough, having problems with maintaining stable body weight, using alcohol in order to relieve stress or negative emotions and being non-religious. Conclusions.Depression among medical students in Poland is common. There are many lifestyle-linked predictors which are associated with this disease in the above-mentioned group. It is crucial to take actions aimed at reducing the high prevalence rates of depression among medical students in Poland, such as introducing routine screening for depression and creating resources that would enable students to obtain help. Key words: medical students; depression

Drożak Paulina, Bryliński Łukasz, Bura Agata, Duda Piotr, Augustowska Katarzyna, Mizerski Grzegorz. Determining environmental predictors of subjective feeling of depressive symptoms among Polish medical students. Journal of Education, Health and Sport. 2020;10(5):133-148. eISSN 2391-8306. DOI http://dx.doi.org/10.12775/JEHS.2020.10.05.014 https://apcz.umk.pl/czasopisma/index.php/JEHS/article/view/JEHS.2020.10.05.014 https://zenodo.org/record/3837614 The journal has had 5 points in Ministry of Science and Higher Education parametric evaluation. § 8. 2) and § 12. 1. 2) 22.02.2019. © The Authors 2020; This article is published with open access at Licensee Open Journal Systems of Nicolaus Copernicus University in Torun, Poland Open Access. This article is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial use, distribution, and reproduction in any medium, provided the original author (s) and source are credited. This is an open access article licensed under the terms of the Creative Commons Attribution Non commercial license Share alike. (http://creativecommons.org/licenses/by-nc-sa/4.0/) which permits unrestricted, non commercial use, distribution and reproduction in any medium, provided the work is properly cited. The authors declare that there is no conflict of interests regarding the publication of this paper. Received: 24.04.2020. Revised: 30.04.2020. Accepted: 21.05.2020. Determining environmental predictors of subjective feeling of depressive symptoms among Polish medical students Paulina Drożak1, Łukasz Bryliński 1, Agata Bura1, Piotr Duda1, Katarzyna Augustowska1, Grzegorz Mizerski1 Chair and Department of Family Medicine, Medical University of Lublin. Abstract Introduction and objective. Depression is a disease that impairs daily functioning. According to research, as much as 27.2% of medical students suffer from depression or show depressive symptoms and 11.1% of them experience suicidal ideation. The aim of the research was to investigate the occurrence of subjective feeling of depressive symptoms among Polish medical students during the course of their medical studies and to determine predictors of this phenomenon that are related to student’s environment. Material and method. A total of 1023 medical students from each year of medical education and different Polish universities took part in the study. The research tool was an author’s questionnaire. Obtained data was subjected to a statistical analysis. To assess the relationship between two variables, the chi-square test of independence was used. The level of significance was set at p < 0.05. Results. The statistical analysis showed that most respondents (52.79%) had noticed symptoms that might had pointed to depression during their medical studies. A statistically significant link was found between subjective feeling of depressive symptoms during the course of medical studies and: mother’s level of education, relationship with parents, relationship with siblings, relationship with friends, knowing a person that one could count on in a difficult situation, knowing a person in which one could trust with all their problems, frequent feelings of loneliness and feeling that one doesn’t participate in social gatherings often enough. Conclusions. The prevalence of subjective feeling of depressive symptoms among medical students is high. Results suggest that good relationships with others are important in prevention of depression. Key words: depression; medical students

Explants of human placental tissue harvested immediately after expulsion were used to determine differences between accumulation of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and polychlorinated dibenzo-p-dioxin (PCDD)-polychlorinated dibenzo-p-furans (PCDF) environmental mixture, and their influence on placental steroidogenesis. Explants were cultured in vitro for 5 days in media supplemented each day with either TCDD or a mixture of PCDD-PCDF. Media were collected every day for steroid content analysis by radioimmunoassay. At 24 h after the last treatment, the tissue was frozen for further analysis of the content of TCDD or other congeners present in the mixture. Determinations of TCDD and all 17 PCDDs and PCDFs were performed using gas chromatography equipped with DB-5 MS and DB-17 capillary columns. In the control tissue, the amounts of both TCDD and mixture components were close to the limit of detection of the method. In the treated tissue, the TCDD accumulation was 94% of the total exposure to TCDD. The most toxic congeners 2,3,7,8-TCDD, 2,3,7,8-tetrachlorodibenzofuran, 1,2,3,7,8-pentachlorodibenzo-p-dioxin (PeCDD), 1,2,3,7,8-pentachlorodibenzo-p-furans (PeCDF) and 2,3,4,7,8-PeCDF showed the highest accumulation, which covered >50% of the total toxic equivalents present in this mixture. During the first 3 days of exposure to TCDD there was no effect on the conversion of dehydroepiandrosterone to oestradiol, whereas on days 4 and 5 of exposure, a twofold decrease in oestradiol secretion was observed. However, a small but significant increase in oestradiol secretion was noted at all times of exposure to the PCDD-PCDF mixture. All observed changes in oestradiol secretion were not accompanied by changes in progesterone secretion after exposure to TCDD or the PCDD-PCDF mixture. In conclusion, a high accumulation of TCDD in the placental tissue resulted in a decrease in oestradiol secretion and in vivo this could result in a decrease in blood flow through the placenta. From the mixture, PeCDD and PeCDF in the higher amount accumulated in the placental tissue caused an increase in oestrogen secretion and as a consequence could activate oxytocin secretion from the pituitary and early pregnancy outcome.

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 changes in hormone production were not due to the action on cell viability. There were time-dependent differences in CYP1A1 expression in cells exposed to TCDD and PCDD/PCDF mixture. Both TCDD and PCDD/PCDF mixture did not induce the DNA damage, as evaluated by the comet assay. Significantly lower DNA migration from the head of comet into the comet tail was noted after the removal of reagents. The highest efficiency of this process was noted 4 h after the TCDD and 24 h after the PCDD/PCDF mixture removal. These results suggest that the DNA adducts and/or DNA—DNA cross-links were formed. Neither TCDD nor PCDD/PCDF mixture had any effect on cell apoptosis assessed by caspase-3 activity and Hoechst 33258. Taken together, these findings clearly indicate a weaker action of the mixture when compared with TCDD. However, in both cases, their action was not due to the induction of the DNA damage and subsequent cell apoptosis but due to a direct influence of these toxicants on placental hormone production. Human & Experimental Toxicology ( 2007) 26, 407—417

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.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. Indirect immunofluorescence for ANP, bcl-2 and p53 expression was used, P production was assayed by direct enzyme immunoassay (EIA) and colorimetric AcDEVD-Pna assay for caspase-3 activity was applied.Stimulation of prepubertal pGCs with FSH resulted in a moderate expression of ANP and elevation in P production. When FSH treatment was followed by LH, the pronounced expression of ANP was observed in all cells. Suppressive effect of FSH and LH on p53 expression and caspase-3 activity with parallel increase in bcl-2 expression and increased P production was observed. The treatment of in vitro luteinized (FSH/LH-stimulated) pGCs with leptin did not influence the expression of ANP. However, in FSH/LH plus leptin treated cells the concomitant increase in bcl-2 expression and parallel inhibitory effect on p53 expression and caspase-3 activity was noted, compared to control cells without any significant increase in P production.The present data demonstrated the positive relationship between ANP expression and P production in pGCs stimulated for luteinization in vitro by FSH and LH, as well as their antiapoptotic role mediated presumably by cGMP accumulation in the luteinized pGCs. A direct anti-apoptotic effect of leptin on in vitro luteinized pGCs, without any significant modulation of P production, was documented.

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. Seventy two-hour exposure to all concentrations of both isomers of DDT and their metabolite DDE stimulated progesterone secretion. Statistically significant decrease in hCG secretion after 24 h and increase in hCG secretion after 72 h exposure for all investigated compounds was noted. Decrease in caspase-3 activity was observed in cells exposed to both isomers of DDT and its metabolites. These findings indicate that both isomers of DDT and their metabolite DDE are able to alter main placental hormone production and survival of JEG-3 cells in the concentration- and time-dependent manner.

The aim of this study was to evaluate the effects of treatment of breast cancer explants with tamoxifen (TMX) or RU486 on GH secretory dynamics in the presence of exogenous estrogen (E2), progesterone (P4) or both. Explants obtained during surgery were divided according to their sex steroid hormone receptor status. P4 (10(-7) M) or 17beta-estradiol (10(-5) M) or both were tested in vitro for their ability to induce hGH secretion and cell proliferation. TMX (10(-7) M) was added to E2, RU486 (10(-7) M) to P4, and both were applied to E2 plus P4-supplemented cultures. The stimulatory action of P4 on GH secretion was noted in hormone-dependent (ER+/PR+) but not in hormone-independent explants (ER-/PR-). RU486 did not abolish this effect. The stimulatory action of P4 on GH release was not parallel to the stimulation of cell proliferation. E2 alone was without effect on GH secretion by both types of breast cancer explants. Combined treatment with both steroids stimulated GH secretion and cell proliferation by (ER+/PR+) explants. Both TMX and RU486 reversed this effect on cell proliferation while only RU486 abolished augmentation of GH secretion. In none of the hormone-dependent breast cancers, the combined treatment with E2 and P4 had any effect on GH secretion and cell proliferation. Taken together, these results lead us to the hypothesis that P4 but not E2 potentiates local GH secretion by hormone-dependent breast cancer explants. The fact that RU486 reversed neither GH secretion nor cell proliferation in hormone-dependent explants indicates its non-receptor-mediated mechanism of action.

Muscle segment homeobox genes, which regulate developmental programs and are expressed in embryonic and adult tissue, play a role in development of some malignancies. There are no reports on the expression of these families of genes in breast cancer tissue. The aim of this study was to compare expression of Msx2 gene in breast cancer of different genotypes as well as in surrounding nonmalignant tissues. Explants obtained during surgery were divided according to their sex steroid receptor status determined by immunocytochemistry. Four explants obtained from malignant and nonmalignant tissue of each individual patient were incubated in a control medium or with the addition of progesterone (10(-7) M) alone, estradiol 17 beta (10(-5) M) or both. The relative level of Msx2 transcripts was evaluated by a semiquantitative RT-PCR and cell proliferation by Alamar Blue test. Results of RT-PCR analysis showed that the relative expression of Msx2 gene depended on the presence of ER/PR receptors both in nonmalignant and malignant tissues Relative amount of Msx2 mRNA was the highest in surrounding nonmalignant ER+/PR- and ER-/PR+ tissue, whereas in ER-/PR- and ER+/PR+ tissue it was 1.4-1.6-fold lower. Tumorigenesis led to about a twofold decrease in the relative amount of Msx2 mRNA except for ER+/PR+ immunophenotype, where no changes were observed. Addition of estradiol or progesterone to the culture of ER-/PR- type tissue explants did not change significantly the relative amount of Msx2 gene mRNA. An opposite effect was observed in ER+/PR- type of tissue. Addition of estradiol alone, or estradiol and progesterone together to tissue culture explants decreased two to three fold the relative amount of Msx2 gene mRNA in both, malignant and surrounding tissues. Progesterone alone had no effect on Msx2 gene expression in this type of tissue. The most complicated regulation was observed in ER+/PR+ type of tissue. Culture of tissue explants supplemented with estradiol significantly increased the relative amount of Msx2 gene mRNA in the surrounding tissue. Progesterone enhanced the stimulatory effect of estradiol in surrounding tissues but not in the malignant tissue. Increased expression of Msx2 correlated with an increased proliferation in ER-/PR- and ER+/PR+ types, but not in ER+/PR- type of tissues. In conclusion, obtained results provide evidence that estrogen affects Msx2 gene expression. Significant changes in the relative amount of Msx2 gene mRNA and lack of canonical ERE element in 5'-upstream sequence of this gene suggest that regulation takes place indirectly probably by protein-protein interaction. The decrease in the relative amount of Msx2 gene mRNA in ER+/PR- type tumor suggests that progesterone also affects Msx2 gene expression by an indirect mechanism(s).

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. Tamoxifen was added to E2-exposed cultures; mifepristone (RU 486) was added to P4, and both were given to E2+P4-supplemented cultures. In hormone-dependent and hormone-independent tissues, treatment with estrogen+progesterone increased IGF-I and IGFBP-2 secretion with concomitant decrease in IGFBP-3, in the same manner as E2 or P4 given alone. Tamoxifen decreased the E2- and E2+P4-stimulated IGF-I secretion by hormone-dependent breast cancer explants. RU 486 decreased the P4- and E2+P4-stimulated IGF-I secretion with parallel stimulation of IGFBP-3 secretion by ER+/PR+ explants. Estradiol and progesterone had a synergistic action on IGFBP-2 secretion by hormone-dependent breast cancer explants. In conclusion, the presented data suggest that there is no synergistic action of E2 and P4 in influencing IGF/IGFBPs ratio and, additionally, suggest a protective action of antiestrogen and antiprogestagen against excessive IGF-I secretion.

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. Recently experimental studies indicated that insulin-like growth factor binding proteins (IGFBPs) might have their own biological actions beyond their ability to regulate insulin-like growth factors (IGFs). Our earlier results showed the progesterone-induced rise in hGH and IGF secretion by human breast cancer explants.To determine the ability of progesterone to stimulate simultaneous local IGF-I and IGFBP-3 secretion by non-malignant and malignant mammary tissue collected from different receptor phenotype tumours.Explants from the tumour and surrounding normal non-malignant tissue were obtained during surging. Breast cancer explants were defined as: ER+ PR+; ER-PR-; ER+ PR-; and ER-PR+. Part of the explants was fixed in 10% buffered formalin for steroid receptor determination by immunohistochemistry. Other parts were cut into small pieces, weight and cultured in Parker medium (M199) supplemented with 5% of calf serum at 37 degrees C in an atmosphere containing 5% CO2 for 48 hours in control medium or with the addition of progesterone (10-7 M). Later media were collected for IGF-I and IGFBP-3 concentration analysis.Progesterone increased (p0.01) IGFBP-3/IGF-I index in ER(-)PR(-) non-malignant tissue and decreased the IGFBP-3/IGF-I index in ER(-)PR(+), ER(+)PR(-) non-malignant explants. That increased the IGF-I bioavailability. Breast malignant explants showed the progesterone induced IGFBP-3/IGF-I index decrease. The decrease was most evident (p0.01) in malignant explants expressing progesterone receptor.Progesterone increased local IGF-I bioavailability in malignant breast tissue. That phenomenon depended on steroid receptor phenotype of breast tissue and was most evident in tissue expressing progesterone receptor. In non-malignant tissue that phenomenon was also found in estrogen receptor expressing tissue. Lack of steroid receptor expression in breast explants reversed that phenomenon.

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. The strongest ANP immunostaining was observed in GC obtained from large follicles. The ANP immunostaining detected by Mab 5D3 had granular appearance moderately expressed in the submembrane region of granulosa cells of all types of follicles. Since ANP and ANP receptors are present in reproductive organs, the three anti-ANP antibodies may be an useful tool in further studies concerning the role of ANP in granulosa cell differentiation and function.

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.Placental cotyledons were harvested immediately after expulsion of placenta. The cells were prepared according to KLIMAN et al. (1986). To examine TCDD and PCDDs/PCDFs mixture action on cytochrome P450 side change cleavage enzyme (P450 scc) and 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) activity the placental cells were cultured either in basal conditions or with the addition of 25-hydroxycholesterol (25-OH) or pregnenolone (P5).TCDD in all doses used decreased basal P4 secretion, while did not show any effect on 25-hydroxycholesterol (25-OH) and pregnenolone (P5) supplemented cultures. In all variants of culture PCDDs/PCDFs mixture was without effect on basal and substrate supplemented progesterone (P4) secretion suggesting a reduction in the activity of cytochrome P450scc or 3 beta-HSD. To examine TCDD and PCDDs/PCDFs mixture action on aromatase cytochrom P450 (P450 arom) activity the placental cells were cultured in basal condition or with the addition of dehydroepi-androsterone (DHEA) or testosterone (T). Significant increase of estradiol secretion under the influence of TCDD in DHEA and T supplemented cultures suggests its action on the activity of P450 arom.The discrepancy found between the action of pure TCDD and dioxin mixture on placental steroids secretion is possibly due to an additional effect of pentachlorodibenzo-p-dioxin (PeCDD) and pentachlorodibenzo-furan (PeCDF) which covered50% of the total toxic equivalents (TEQ) present in this mixture.