• Animal cells and systems
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• v.13 no.3
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• pp.339-344
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• 2009

This study aims to find out the effect of heavy metals, as is the case of EDCs (endocrine disrupting chemicals), on reproductive endocrine disruption of aquatic animals. In the present experiment zinc, which is a heavy metal well known for its androgenous activity, was used. The experimental period was 24 weeks, starting in November during the inactive stage of the clam's reproductive cycle. The experimental groups were composed of one control condition and three zinc exposure conditions (0.64, 1.07, and 1.79 mg/L). The sex ratio (F:M) was 1:1.06 in the control group and 1:1.70 in all the exposed group, illustrating the tendency for higher proportion of males with increases in zinc concentration. Gonad maturity was higher in 1.07, and 1.79 mg/L groups compared to the control group, with higher maturity observed in males than females. Intersex individuals made up 24.7% of the exposed group, while females exhibited a higher ratio than the males with increasing zinc concentration. The results of this study indicate that zinc functions as an androgenic effector on the reproduction of Gomphina veneriformis.

• Environmental Analysis Health and Toxicology
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• v.29
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• pp.2.1-2.7
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• 2014

Objectives Heat shock protein 90 (HSP90) is a highly conserved molecular chaperone important in the maturation of a broad spectrum of protein. In this study, an HSP90 gene was isolated from Asian paddle crab, Charybdis japonica, as a bio-indicator to monitor the marine ecosystem. Methods This work reports the responses of C. japonica HSP90 mRNA expression to cellular stress by endocrine disrupting chemicals (EDCs), such as bisphenol A (BPA) and 4-nonylphenol (NP) using real-time. reverse transcription polymerase chain reaction. Results The deduced amino acid sequence of HSP90 from C. japonica shared a high degree of homology with their homologues in other species. In a phylogenetic analysis, C. japonica HSP90 is evolutionally related with an ortholog of the other crustacean species. The expression of HSP90 gene was almost distributed in all the examined tissues of the C. japonica crab but expression levels varied among the different body parts of the crabs. We examined HSP90 mRNA expression pattern in C. japonica crabs exposed to EDCs for various exposure times. The expression of HSP90 transcripts was significantly increased in C. japonica crabs exposed to BPA and NP at different concentrations for 12, 24, 48 and 96 hours. The mRNA expression of HSP90 gene was significantly induced in a concentration- and time-dependent manner after BPA or NP exposures for 96 hours. Conclusions Taken together, expression analysis of Asian paddle crab HSP90 gene provided useful molecular information about crab responses in stress conditions and potential ways to monitor the EDCs stressors in marine environments.

• Korean Journal of Microbiology
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• v.52 no.3
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• pp.306-312
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• 2016

Microalgae are the potential bioindicators of environmental changes, for the environmental risk assessment as well as to set limits for toxic chemical release in the aquatic environment. Here, we evaluated the effects of two endocrine disrupting chemicals (EDCs), namely bisphenol A (BPA) and Aroclor 1016, on the green algae Tetraselmis suecica, diatom Ditylum brightwellii, and dinoflagellate Prorocentrum minimum. Each species showed wide different sensitivity ranges when exposed to these two EDCs; the 72 h effective concentration ($EC_{50}$) for these test species showed that Aroclor 1016 was more toxic than BPA. $EC_{50}$ values for the diatom D. birghtwellii were calculated at 0.037 mg/L for BPA and 0.002 mg/L for Aroclor 1016, representing it was the most sensitive when compared to the other species. In addition, these results suggest that these EDC discharge beyond these concentrations into the aquatic environments may cause harmful effect to these marine species.

• Environmental Analysis Health and Toxicology
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• v.25 no.4
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• pp.287-294
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• 2010

Objectives : The aim of this study was to verify the intersexuality of Crassostrea gigas and Ruditapes philippinarum in southern coastal waters of Korea. Methods : Specimens of Crassostrea gigas (n=363) were collected from six areas of Tongyeong, Geoje and Yeosu. Ruditapes philippinarum (n=221) was collected from five areas of Yeosu. The sex ratio and intersexuality were determined after observing gonad preparations. Results : The rate of intersexuality in Crassostrea gigas was 16.25%, with females (24.79%; n=30/121) exhibiting a higher rate than males (11.98%; n=29/242). The rate of intersexuality in Ruditapes philippinarum was 24.43%, with females (37.76%; n=37/98) exhibiting a higher rate than males (13.82%; n=17/123). Conclusions : The results of this study suggest that intersexuality is induced by aquatic pollutants such as endocrine disrupting chemicals (EDCs).

• Biomolecules & Therapeutics
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• v.8 no.1
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• pp.78-83
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• 2000

The objective of this study was to prevalidate the Organization for Economic Cooperation and Development's (OECD) rodent uterotrophic assay as a test method for screening of potential endocrine disrupting chemicals (EDCs). This study was conducted exactly as described in the OECD protocol documents. A positive control substance, 17$\alpha$-ethinyl estradiol (EE), was administered daily for three days to ovariectomized (OVX) Sprague-Dawley rats at various doses for determine the dose-response curve. Additionally, a pure antiestrogenic chemical, ZM189, 154 was administered to OVX rats at the same time EE to determine the effectiveness of the material against blocking the estrogenic effects of EE. At higher concentration of EE (10 $\mu\textrm{g}$/kg), a statistically significant difference in body weight gain and food consumption was observed compared to vehicle controls. In uterine responses, EE produced a dose-related increase in uterus weights compared to vehicle control. These increases were statistically significant at the >1.0 $\mu\textrm{g}$/kg doses. However, a similar dose-response relationship was not observed in vagina weight. A comparison of the two groups receiving ZM189,154 (0.1 and 1.0 mg/kg) with 0.3 $\mu\textrm{g}$/kg of EE and the group receiving only 0.3 $\mu\textrm{g}$/kg of EE showed dose-related decreases in uterus weights. However, statistical significance was shown in 1.0 mg/kg of ZM189,154. In conclusion, administration of EE produced a dose-related increase in uterine (wet and blotted) weights. Additionally, the 1.0mg/kg dose of ZM189,154 was effective in blocking the estrogenic activity of EE. These data suggest 3-day uterotrophic assay using OVX rats may serve as a good tool for EDCs screening.

• Environmental Analysis Health and Toxicology
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• v.22 no.3
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• pp.203-209
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• 2007

생활하수, 공장폐수, 농경유출수에 의해 수생태계로 유입된 다양한 화학물질들은 수서곤충이나 어류와 같은 수생생물에게 나쁜 영향을 주곤 한다. 비스페놀A와 노닐페놀을 포함하는 많은 화학물질들이 내분비계 장애물질(EDCs)로 의심되고 있고, 그들은 환경속에서 서로 다른 혼합형태로 공존하기도 한다. 따라서 비스페놀A와 노닐페놀의 혼합물이 독성과 생식학적 반응에 미치는 영향을 살펴보기 위해 일본산 송사리의 수정란 치사율, 부화율 및 부화시간, 치어의 성장율 및 비텔로제닌 농도 등이 측정되었다. 수정된 지 24시간 이내의 수정란을 대조군, 양성대조군($17{\beta}-estradiol$), 그리고 서로 다른 농도의 비스페놀A와 노닐페놀의 혼합물에 부화 후 60일까지 유수식 조건하에 노출시켰다. 수정란${\sim}$치자어 단계에서는 대조군과 비교하여 실험군의 치사율 및 부화율, 부화시간에 차이가 나타나지 않았으며, 부화 후 60일간의 노출 후 성장(길이, 무게)에 있어서도 비록 양성대조군에서 낮은 성장상태를 보였지만 다른 혼합물의 실험군들과는 차이를 보이지 않았다. 한편 체내 비텔로제닌 농도는 혼합물의 농도증가에 따라 증가하였으며 수컷의 경우 최저농도의 혼합물(Treatment A)을 제외한 실험군에서 농도증가에 따라 증가하였다. 반면 양성대조군의 경우 수컷이 발견되지 않았고 암컷 체내의 비텔로제닌 농도는 최고농도의 혼합물(Treatment D) 실험군과 비슷한 경향을 보였다. 위 실험을 통해 각각의 내분비계 장애물질이 개별적으론 생식발달 및 비텔로제닌 유도에 무영향농도(NOEC)라 하더라도 혼합된 경우 영향이 나타날 수 있다는 것을 보여주었으며, 이는 수환경 내 다양한 화학물들의 혼합효과(combination effect)가 생태위해성평가를 좀더 면밀하게 하기 위해서 주의 깊게 고려되어야 한다고 제안한다.

• Journal of Wetlands Research
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• v.9 no.1
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• pp.79-89
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• 2007

This paper provides a comprehensive overview of the present status of several environmental problems caused by emerging toxic substances such as persistent organic pollutants (POPs), endocrine disrupting chemicals (EDCs), and arsenic in various environmental media in Vietnam. Monitoring data reported during the 1990s demonstrated elevated contamination of DDTs in most of these compartments in Vietnam. Studies in frame of the Asia-Pacific Mussel Watch Program revealed that fish, mussels and resident birds from Vietnam contained higher concentrations of DDTs as compared to other countries in region, suggesting the role of Vietnamese environment as a significant emission source of DDT in the Southeast Asian region. The estimated dietary intakes of PCBs and DDTs for Vietnamese were relatively high among Asian developing countries, suggesting potential risk for humans posed by thesechemicals. Widespread contamination of some endocrine active compounds such as alkylphenols and phthalates was observed at various sites along the coasts of northern and middle Vietnam. The presence of significant source of bisphenol-A along Red River estuary was revealed with the concentrations comparable to those reported for developed nations. A case study on seasonal variation of alkylphenols and phthalates in surface water of river delta and estuary of north and middle Vietnam indicated the differences in distribution of these compounds between dry and rainy seasons. Higher concentrations of alkylphenols and phthalates were found in dry season in estuary; while the contrasting pattern was observed in the river delta, showing elevated residues in rainy season. This result suggests the different behavior of alkylphenols and phthalates in river delta and coastal environment. From ecotoxicological perspectives, concentrations of bis-phenol A and di(2-ethylhexyl)phthalates [DEHP] in surface water from some locations in Vietnam exceeded the guideline values for Ecotoxicological Effects and the Environmental Risk Limit, respectively, suggesting potential for toxic implications on aquatic wildlife. Widespread and elevated arsenic contamination was discovered inour recent surveys in groundwater in a large area of suburban areas of Hanoi city, the capital of Vietnam. The most recent investigation in 4 villages showed about more than 50 % of groundwater samples contained As concentrations exceeding 50 g/L (the WHO and Vietnamese standard). In particular, in Son Dong villages, 58 % of samples analyzed contained As concentrations higher than 200 g/L. Good correlations were found in As concentrations in water and hair and urine of peoples in corresponding families, suggesting the chronic exposure to As by people living in As-contaminated ground water areas. In Son Dong village, As levels in hair (mean: 1.7 mg/kg dry wt) and urine (g/g creatinine) exceeding the reference values recommended by WHO, suggesting potential for human risk posed by long term accumulation of As in human body. Future studies should be focused on the time trends of POPs and EDCs in biota in Vietnam in order to predict future trend of contamination and to reveal new clues for understanding possible toxic impacts on aquatic organisms. The issues of arsenic contamination in groundwater and their chronic toxic implications on human health should be systematically investigated in the future.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.11
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• pp.5445-5450
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• 2012

Although benign uterine leiomyomata (LMA) is the most common reproductive tumor in premenopausal women, its etiology is largely unknown. We aimed in the present study to demonstrate the potential role of environmental factors with estrogenic activity in tumor etiology by focusing on the role of aryl hydrocarbon receptor (AhR) which mediates the effects of many environmental endocrine disruptors and contributes to the loss of normal ovarian function in polluted environments. This case-control study aimed to compare the interactions between AhR and lifestyle factors in a clinical setting for the first time among 138 newly diagnosed LMA patients and 138 normal controls who lived in Tehran and Mashhad, respectively, during the last 10 years. To conduct immunohistochemical studies using appropriate monoclonal antibodies, 30 cases were selected retrospectively from 2009-2011 from the pathology departments of two university hospitals in Tehran. Although the levels of sex steroid receptors were similar in adjacent myometrium and uterine leiomyomas of all cases, AhR was significantly overexpressed (p=0.034, OR=1.667) in uterine LMA and this overexpression was correlated with living in Tehran [(p=0.04, OR=16 (1.216-210.58)], smoking[P=0.04, OR=2.085 (1.29-3.371)], living near polycyclic aromative hydrocarbon producing companies [p=0.007, OR=2.22 (1.256-3.926)] and eating grilled meat [p=0.042, OR=1.28 (1.92-3.842)]. Our study contributes to the understanding of the effects of EDCs on AhR levels as well as women's health and points out possible risk factors for the development and growth of uterine LMA. It seems that the development of LMA could be the result of interactions between hormonal and environmental factors.

• Toxicological Research
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• v.31 no.4
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• pp.331-337
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• 2015

Synthetic pyrethroids (SPs) are the most common pesticides which are recently used for indoor pest control. The widespread use of SPs has resulted in the increased exposure to wild animals and humans. Recently, some SPs are suspected as endocrine disrupting chemicals (EDCs) and have been assessed for their potential estrogenicity by adopting various analyzing assays. In this study, we examined the estrogenic effects of lambda-cyhalothrin (LC) and cypermethrin (CP), the most commonly used pesticides in Korea, using BG-1 ovarian cancer cells expressing estrogen receptors (ERs). To evaluate the estrogenic activities of two SPs, LC and CP, we employed MTT assay and reverse-transcription polymerase chain reaction (RT-PCR) in LC or CP treated BG-1 ovarian cancer cells. In MTT assay, LC ($10^{-6}M$) and CP ($10^{-5}M$) significantly induced the growth of BG-1 cancer cells. LC or CP-induced cell growth was antagonized by addition of ICI 182,720 ($10^{-8}M$), an ER antagonist, suggesting that this effect appears to be mediated by an ER-dependent manner. Moreover, RT-PCR results showed that transcriptional level of cyclin D1, a cell cycle-regulating gene, was significantly up-regulated by LC and CP, while these effects were reversed by co-treatment of ICI 182,780. However, p21, a cyclin D-ckd-4 inhibitor gene, was not altered by LC or CP. Moreover, $ER{\alpha}$ expression was not significantly changed by LC and CP, while down-regulated by E2. Finally, in xenografted mouse model transplanted with human BG-1 ovarian cancer cells, E2 significantly increased the tumor volume compare to a negative control, but LC did not. Taken together, these results suggest that LC and CP may possess estrogenic potentials by stimulating the growth of BG-1 ovarian cancer cells via partially ER signaling pathway associated with cell cycle as did E2, but this estrogenic effect was not found in in vivo mouse model.

• Proceedings of the Korea Society of Environmental Toocicology Conference
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• 2003.10a
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• pp.173-173
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• 2003

With the introduction of DNA microarrays, a high throughput analysis of gene expression is now possible as a replacement to the traditional time-consuming Southern-blot analysis. This cDNA microarray should be ahighly favored technology in the area of molecular toxicology or analysis of environmental stresses.In this study, therefore, we developed a novel cDNA microarray for analyzing stress-specific responses in japanese Medaka fish. In the design and fabrication of this stress specific functional cDNA microarray, 123 different genes in Medaka fish were selected from eighteen different stress responsive groups and spotted on a 25${\times}$75 mm glass surface. After exposure of the fish to bisphenol A which is the one of the well-known endocrine disrupting chemicals (EDCs), over 1 or 10 days, the responses of the DNA chip were found to show distinct expression patterns according to the mode of toxic actions from environmental toxicants. As a results, they showed specific gene expression pattern to bisphenol A, additionally, the chemical spesific biomarkers could be suggested based on the chip analysis data. Therefore, this chip can be used to monitor stress responses of unknown and/or known toxic chemicals using Medaka fish and may be used for the further development of biomarkers by utilizing the gene expression patterns for known contaminants.