• Toxicological Research
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• 제18권4호
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• pp.331-339
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• 2002

Phenoxy compounds, 2,4-Dichlorophenol acetoxy acid (2,4-D) and 2,4-dichlorophenol (DCP), are widely used as a hormonal herbicide and intermediate for pesticide manufacturing, respectively. In order to assess the potential of these compounds as endocrine disruptors, we studied the androgenicity of them wing in vivo and in vitro androgenicity assay system. Administration of 2,4-D (50 mg/kg/day, p.o.) or DCP (100 mg/kg/day, p.o.) to rats caused an increase in the tissue weight of ventral prostate, Cowpers gland and glands penis. These increase of androgen-dependent tissues were additively potentiated when rats were simultaneously treated with low dose of testosterone (1 g/kg, s.c.). 2,4-D increased about 350% of the luciferase activity in the PC cells transiently cotransfected phAR and pMMTV-Luc at concentration of $10^{-9}$ M. In 2,4-D or DCP-treated castrated rats, testosterone 6$\beta$-hydroxylase activity was not significantly modulated even when rats were co-treated with testosterone. In vitro incubation of 2,4-D and DCP with microsomes at 50 $\mu$M inhibited testosterone 6$\beta$-hydroxylase activity about 27% and 66% in rat liver microsomes, about 44% and 54% in human liver microsomes and about 50% and 45% in recombinant CYP3A4 system, respectively. The amounts of total testosterone metabolites were reduced about 33% and 75% in rat liver microsomes, 69% and 73% in human liver microsomes and 54% and 64% in recombinant CYP3A4 by 2,4-D or DCP, respectively. Therefore, the additive androgenic effect of 2,4-D or DCP by the co-administration of the low dose of testosterone may be due to the increased plasma level of testosterone by inhibiting the cytochrome P450-mediated metabolism of testosterone. These results collectively suggested that 2,4-D and DCP may act as androgenic endocrine disrupter by binding to the androgen receptor as well as by inhibiting the metabolism of testosterone.

• Biomolecules & Therapeutics
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• 제8권2호
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• pp.147-152
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• 2000

The rodent uterotrophic assay is currently recommended as one of the primary in vivo assays far endocrine disrupting chemicals by the Organization for Economic Cooperation and Development (OECD) and Endocrine Disruptor Screening and Testing Advisory Committee (US EPA EDSTAC). Generally, this assay relies on the rapid increase in uterus and vagina weights when exposed to estrogenic compounds. Phthalate esters have been used extensively as a plasticizer in the manufacture of plastic products such as PVC films and medical devices. Recently, phthalate esters have been shown to induce endocrine system mediated responses. However, a flew studies have been conducted for the screening of their estrogenic activity. In this study the estrogenic activity of seven phthalate esters, butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP), di-n-butylphthalate (DBP), diethylphthalate (DEP), di-n-pentylphthalate (DPF), di-n-propylphthalate (DPrP) and dicyclohexylphthalate (DCHP), was examined in uterotrophic assay. Phthalate esters dissolved in corn oil were administered to ovariectomized (OVX) female Sprague-Dawley rats by sub-cutaneous injection for three consecutive days. fiats were sacrificed 24h after final treatment, and then uterus and vagina weights were deter mined. All phthalate esters tested in this assay did not change talc uterus and vagina weights at dosage levels up to 200 mg/kg/day treatment. These results demonstrated that phthalate esters did not exhibit estrogenic activity in vivo uterotrophic assay.

• 한국환경성돌연변이발암원학회지
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• 제22권4호
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• pp.259-265
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• 2002

Phthalate analogues are a plasticizer and solvent used in industry. Phthalates were reported to be a potential carcinogen classified in the category of suspected endocrine disruptors. Most common human exposure to these compounds may occur with contaminated food. They may migrate into food from plastic wrap or may enter food from general environmental contamination. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of phthalates that possibly threaten the public health. Concern about their use has been mounting. To screen and elucidate the endocrine disrupting activity and their mechanism of phthalate analogues, first of all, E-screen assay was performed in MCF7 human breast cancer cells with seven phthalate analogues. In this cell proliferation assay, only dibutyl phthalate (DBP) showed weak estrogenic activity. Also the yeast-based transcription assay to assess the interactions of DBP with the estrogen, androgen, and progesterone receptors was conducted. DBP in the concentration ranges from 10$^{-16}$ to 10$^{-11}$ M was active in the estrogen transcriptional assay, but it did not show the effect on $\beta$-galactosidase activity in the progesterone and androgen transcriptional assays. These data indicate that DBP shows estrogenic potential and can be classified as weak and/or suspected endocrine disrupting chemicals.

• 한국환경성돌연변이발암원학회지
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• 제26권2호
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• pp.53-58
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• 2006

Normally, environmental toxicants are classified as endocrine disruptors if they interfere with regulation of cellular function by endogeneous steroids through inhibition of receptor binding and/or transcriptional activation. So, many studies have been performed about agonist/antagonist of hormone receptor to study mechanisms of endocrine disruptors. If toxicants affect steroid biosynthesis and/or degradation and alter hormone homeostasis, these also are classified as endocrine disruptors. But there are not many studies of the mechanisms of endocrine disruptors on the basis of alteration of steroid biosynthesis and/or degradation. Isolation and culture of Leydig cells from testis is one of methods for the steroidogenesis screening assays to evaluate a substance for altering steroidogenesis. Leydig cells were harvested using the method described by Klinefelter with modifications. Leydig cells were purified by perfusion of testis and incubation ($34^{\circ}C$, 80cycles/minute, 20 minutes) with collagenase (0.25 mg/kg), centrifugal elutriation, percoll gradient centrifugation and BSA multidensity gradient centrifugation. To confirm if this method is one of appropriate tools to evaluate a substance for altering steroidogenesis, ketoconazole, positive control was administered to purified Leydig cells. Ketoconazole ($10^{-8}M$ and above) significantly reduced testosterone production in purified Leydig cells. From above results, we suggest that this method for steroidogenesis screening assay appears to be a appropriate tool to detect suspected compounds for altering steroidogenesis.

• 분석과학
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• 제12권3호
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• pp.248-255
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• 1999

국내 주요 하수 슬러지(Z-1, Z-2시)에서 내분비계 장애물질로 의심 받는 여러 가지 물질 중 octylphenol(OP), nonylphenol(NP), di-octylphthalate(DOP)를 이 염화메탄을 이용하여 Soxhlet 장치로 추출한 후 GC/MS-SIM 방법으로 그들의 함량을 결정하였다. Z-1시 하수 슬러지의 경우 octylphenol, nonylphenol, di-octylphthalate의 함량이 각각 $3.25{\pm}0.07{\mu}g/g$, $1168{\pm}36{\mu}g/g$, $1172{\pm}57{\mu}g/g$이었고, Z-2 하수 슬러지는 octylphenol, nonylphenol, di-octylphthalate가 각각 $0{\mu}g/g$, $10.8{\pm}0.1{\mu}g/g$, $80{\pm}62{\mu}g/g$이 검출되었다. 특히 Z-1하수 슬러지에서 검출된 nonylphenol과 di-octylphthalate의 양은 매우 높은 값으로 생태계로 순환될 경우 매우 위험한 수준으로 평가되었으며, 또한 인간의 건강과 생식능력에 영향을 미칠 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제16권11호
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• pp.1740-1746
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• 2006

Enrichment techniques led to the isolation of a Pseudomonas sp. strain P2 from municipal waste-contaminated soil sample, which could utilize different isomers of a commercial mixture of 4-nonylphenol when grown in the presence of phenol. The isolate was identified as Pseudomonas sp., based on the morphological, nutritional, and biochemical characteristics and 16S rDNA sequence analysis. The ${\beta}$-ketoadipate pathway was found to be involved in the degradation of phenol by Pseudomonas sp. strain P2. Gas chromatography-mass spectrometric analysis of the culture media indicated degradation of various major isomers of 4-nonylphenol in the range of 29-50%. However, the selected ion monitoring mode of analysis of biodegraded products of 4-nonylphenol indicated the absence of any aromatic compounds other than those of the isomers of 4-nonylphenol. Moreover, Pseudomonas sp. strain P2 was incapable of utilizing various alkanes individually as sole carbon source, whereas the degradation of 4-nonylphenol was observed only when the test organism was induced with phenol, suggesting that the degradation of 4-nonylphenol was possibly initiated from the phenolic moiety of the molecule, but not from the alkyl side-chain.

• Journal of Animal Science and Technology
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• 제56권7호
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• pp.26.1-26.10
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• 2014

Background: Endocrine disruptors are exogenous substance, interfere with the endocrine system, and disrupt hormonal functions. However, the effect of endocrine disruptors in different species has not yet been elucidated. Therefore, we investigated the possible effects of $17{\beta}$-estradiol (E2), progesterone (P4), genistein (GEN) and 4-tert-octylphenol (OP), on capacitation and the acrosome reaction in bovine, mouse, and porcine spermatozoa. In this in vitro trial, spermatozoa were incubated with $0.001-100{\mu}M$ of each chemical either 15 or 30 min and then assessed capacitation status using chlortetracycline staining. Results: E2 significantly increased capacitation and the acrosome reaction after 30 min, while the acrosome reaction after 15 min incubation in mouse spermatozoa. Simultaneously, capacitation and the acrosome reaction were induced after 15 and 30 min incubation in porcine spermatozoa, respectively. Capacitation was increased in porcine spermatozoa after 15 min incubation at the lowest concentration, while the acrosome reaction was increased in mouse spermatozoa after 30 min (P < 0.05). E2 significantly increased the acrosome reaction in porcine spermatozoa, but only at the highest concentration examined (P < 0.05). P4 significantly increased the acrosome reaction in bovine and mouse spermatozoa treated for 15 min (P < 0.05). The same treatment significantly increased capacitation in porcine spermatozoa (P < 0.05). P4 significantly increased capacitation in mouse spermatozoa treated for 30 min (P < 0.05). GEN significantly increased the acrosome reaction in porcine spermatozoa treated for 15 and 30 min and in mouse spermatozoa treated for 30 min (P < 0.05). OP significantly increased the acrosome reaction in mouse spermatozoa after 15 min (P < 0.05). Besides, when spermatozoa were incubated for 30 min, capacitation and the acrosome reaction were higher than 15 min incubation in E2 or GEN. Furthermore, the responsiveness of bovine, mouse and porcine spermatozoa to each chemical differed. Conclusions: In conclusion, all chemicals studied effectively increased capacitation and the acrosome reaction in bovine, mouse, and porcine spermatozoa. Also we found that both E2 and P4 were more potent than environmental estrogens in altering sperm function. Porcine and mouse spermatozoa were more responsive than bovine spermatozoa.

• 공업화학
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• 제27권3호
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• pp.259-264
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• 2016

본 연구에서는 norbonene dialkyl ester 6종을 isoprene rubber에 적용하여 내분비계 교란물질인 DEHP에 대한 대체 가능성을 평가하였다. IR 시편은 isoprene rubber (IR)와 norbonene dialkyl ester, 가황제 등을 배합하여 제작하였으며, 토크값, 스코치 시간, 최적가황시간, 무니점도를 측정하여 가공성을 평가하였고, 경도, 인장강도, 100% modulus, 신율 등물성을 평가하여 이를 DEHP를 적용한 경우와 비교하였다. 그 결과 토크 값의 경우 최저토크, 최대토크 모두 DEHP 보다 낮거나 유사한 값을 나타내었고, 스코치 시간, 최적가황시간은 DEHP보다 같거나 길게 측정되었다. 무니점도는 DEHN이 낮은 값을 나타내어 DEHP를 첨가한 경우보다 가공성이 우수함을 확인하였다. 경도와 열적 특성의 경우 norbornene계 화합물이 DEHP와 같거나 유사한 경향을 보였다. 인장특성의 경우 선형의 알킬기를 가진 norbornene계 화합물을 적용한 경우가 우수함을 확인하였다.

• 대한환경공학회지
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• 제32권5호
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• pp.443-454
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• 2010

프탈레이트 화합물은 PVC 수지 등의 가소제로 널리 사용되며, 내분비계장애 및 돌연변이를 유발하는 물질로서 이에 대한 독성은 널리 알려져 있다. 우리나라에서는 소비자용품이나 음용수에서의 프탈레이트 화합물에 대한 측정 사례는 찾아 볼 수 있으나, 대기환경분야에서의 측정사례는 전무한 실정이다. 본 연구에서는 환경대기 중의 프탈레이트 화합물을 측정하기 위해 고용량샘플러로 시료를 채취한 후 속슬렛 장치로 추출하여 GC/MS로 분석하였다. 일부 시료에 대하여 저용량공기채취법과 고용량공기채취법을 동시에 적용하여 두 측정 결과를 비교 평가하였다. 분석대상 항목은 dimethyl phthalate (DMP), diethyl phthalate (DEP), di-n-butyl phthalate (DBP), butyl benzyl phthalate (BBP), di(2-ethylhexyl) phthalate (DEHP) 및 di-n-octyl phthalate (DOP) 등 6개 항목을 선정하였다. 입자상 시료 채취를 위해서는 석영섬유여지를 사용하였으며, 기체상 시료 채취에는 PUF/XAD-2를 사용하였다. 실험실 정도관리 평가 결과 표준시료에 대한 선형성과 재현성은 우수한 결과를 나타내었으며, 정량검출한계는 항목에 따라 대기 중 농도로 환산하여 0.60~17.84 ng/$m^3$ 수준으로 추정되었다. 또한 실제 현장평가를 위해 2007년 1월과 6월에 시화 반월공단 (정왕2동, 원시동)에서 측정한 결과 비교적 분자량이 작고 끓는점이 낮은 DMP, DEP, DBP는 기체상에 많이 존재하며, DBP 보다 분자량이 크고 끓는점이 높은 DEHP와 DOP는 입자상에 주로 존재하는 것으로 나타났다. DEHP는 45.7 ng/$m^3$ ~ 1012.7 ng/$m^3$, DMP는 7.7 ng/$m^3$ ~ 375.1 ng/$m^3$ 수준으로 검출되었다. 전반적으로 볼 때 환경대기 중의 프탈레이트 화합물 측정에는 고용량시료채취법이 저용량법보다 우수한 것으로 나타났다.

• 한국발생생물학회지:발생과생식
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• 제10권4호
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• pp.255-261
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• 2006

일부 식물성 에스트로겐(phytoestrogen)의 경우, 긍정적인 효과를 갖는 것으로 보이지만, 대부분의 내분비계 장애 물질(endocrine disruptor 또는 endocrine disrupting compound, EDC)은 노출된 개체의 내분비계를 교란시켜 인간이나 야생 동물의 건강에 해로운 것으로 알려져 있다. 선행 연구에서 본 연구자들은 사춘기 전에 단기간으로 식물성 에스트로겐인 genistein(GS)을 투여했을 때 암컷 흰쥐의 생식계가 활성화되어 조기 사춘기가 유도되지만, 플라스틱 가소제인 di(2-ethyl hexyl)phthalate(DEHP)를 투여했을 때 반대로 생식계의 불활성화가 유도되어 사춘기 지연이 초래됨을 보고하였다. 본 연구에서는 사춘기전 GS 또는 DEHP 투여가 흰쥐 난소와 자궁에서의 성적인 성숙 상태를 반영하는 에스트로겐 수용체($ER\;{\alpha}$ and $ER\;{\beta}$)와 LH 수용체(LHR) 발현에 미치는 효과를 조사하였다. GS(100 mg/kg/day i.p.)를 생후 25일부터 사춘기 개시의 지표인 최초의 질구 개방(vaginal opening, VO)이 일어나는 날까지 투여하고 다음 날(day 32) 희생시켰다. 유사하게, DEHP(100 mg/kg/day i.p.)를 생후 25일부터 대조군(corn oil $200\;{\mu}L$)에서 최초 질구 개방(vaginal opening, VO)이 일어나는 날까지 투여하고 다음 날(day 36) 희생시켰다. 희생 직후 난소와 자궁의 total RNA를 추출하여 각 호르몬 수용체들의 전사 수준을 측정하기 위해 정량적인 RT-PCR을 수행하였다. GS 투여에 의해 자궁에서의 $ER\;{\alpha}$, $ER\;{\beta}$ 그리고 LHR mRNA 수준 모두 대조군에 비해 유의하게 증가하였다. GS군의 난소에서는 LHR 발현이 유의하게 증가하였으나 $ER\;{\alpha}$와 $ER\;{\beta}$의 발현은 증가하는 경향만을 보였다. 한편, DEHP군에서는 난소와 자궁에서의 $ER\;{\alpha}$, $ER\;{\beta}$ 그리고 LHR mRNA 수준은 모두 대조군에 비해 유의하게 감소하였다. 사춘기 전의 암컷 흰쥐의 난소와 자궁에서 성숙과 관련된 생식호르몬 수용체들의 발현 변화는 이들 조직의 무게와 해부학적인 변화, 그리고 혈중 생식호르몬들의 수준 등 사춘기 과정에서의 표현형적인 측면 변화-2차 성징-들을 반영하는 것으로 추정된다.