• Animal cells and systems
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• 제11권1호
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• pp.1-8
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• 2007

Recently, we have shown that some endocrine disruptors, heavy metals, organotins and azoles suppressed steroidogenic enzymes such as P450 side-chain cleavage enzyme (P450scc) and aromatase in bullfrog ovarian follicles. In the present study, by using an amphibian ovarian follicle culture system, we examined the effects of these endocrine disruptors on maturation and ovulation of oocytes from Rana dybowskii in vitro. Ovarian fragments or isolated follicles were cultured for 24 h in a medium containing frog pituitary homogenate (FPH) or progesterone ($P_{4}$) with or without endocrine disruptors, and oocyte maturation (germinal vesicle breakdown, GVBD) and ovulation were examined. Among the organotins, tributyltin (TBT) strongly inhibited both FPH-and $P_{4}-induced$ oocyte maturation ($ED_{50}$:0.6 and 0.7 ${\mu}M$, respectively); however, tetrabutyltin (TTBT) and dibutyltin (DBT) showed only partial suppression, while monobutyltin (MBT) showed no inhibitory effect. All of the organotins suppressed $P_{4}-induced$ oocyte ovulation very effectively at a low concentration, and TBT and DBT exerted an inhibitory effect on FPH-induced ovulation. Among the heavy metals, mercury (Hg), cadmium (Cd) and cobalt (Co) were very effective in inhibiting FPH-induced oocyte maturation and ovulation, while lead (Pb), arsenite (As) and zinc (Zn) were less effective. However, all of the heavy metals suppressed FPH-induced oocyte ovulation at a high dose ($100{\mu}M$). Among the azoles, itraconazole (ICZ), ketoconazole (KCZ) and clotrimazole (CTZ) effectively inhibited FPH-induced oocyte maturation and ovulation, while econazole (ECZ), miconazole (MCZ) and fluconazole (FCZ) were considerably less effective. These results demonstrated that the abovementioned endocrine disruptors exhibited differential effects on oocyte maturation and ovulation in amphibian follicles and that the frog ovarian culture system could be used as an effective experimental tool to screen and evaluate the toxicity of various endocrine disruptors in vitro.

• Toxicological Research
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• 제17권1호
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• pp.65-71
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• 2001

The key targets of endocrine disruptors are nuclear hormone receptors, which bind to steroid hormones and regulate their gene transcription. A yeast-based steroid hormone receptor gene trascription assay was previously developed for the evaluation of chemicals with endocrine modulating activity. The yeast transformants used in this assay contain the human estrogen receptor along with the appropriate steroid response elements upstream of the $\beta$-galactosidase reporter gene. We tried to evaluate several natural and synthetic steroids of their potential to interact directly with the steroid receptor. Some putative endocrine disruptors, including nonylphenol, are weakly estrogenic. But the combined treatment oj these chemicals with di-(2-ethylhexyl)phthalate (DEHP) significantly increased the $\beta$-galactosidase activity in the yeast transformant. These results suggest that we also have to consider the synergistic effects of endocrine disruptors. In this study, we showed that yeast-based bioassay is a valuable tool for screening potential endocrine disruptors and quantitative determination of estrogenicity. And the possibility that the estrogen receptor binds multiple environmental chemicals adds another level of complexity to the interaction between the endocrine disruptors and the human hormone system.

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2006년도 The 5th Biannual Meeting of Pacific Rim Society for Fertility and Sterility
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• pp.171.2-171.2
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• 2006

• 한국식품위생안전성학회지
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• 제21권4호
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• pp.258-262
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• 2006

환경호르몬 물질의 생체내에서의 상호작용에 의한 상자 또는 상승 작용을 알아보기 위하여 환경호르몬 물질들을 조합하여 마우스에 처치한 후 생체내에서 생식기의 변화 정도를 조직병리학적으로 관찰하였다. 암컷 ICR마우스에 난소적출술을 실시하고 2주 후에 DEHP, DBP, BPA의 환경호르몬 물질을 단독 또는 두개씩 조합하여 마우스에 피하로 주입하였다. 육안적인 변화에서는 모든 군에서 이상이 관찰 되지 않았으며, 부검 후 자궁의 무게를 측정한 결과에 있어서도 유의적인 변화를 관찰할 수 없었으나, 자궁 내 fluid존재에 있어서는 E2 단독 투여 군과 E2와 함께 투여한 모든 그룹(E2+DEHP, E2+DBP, E2+BPA)에서 관찰되었다. 조직병리학적인 관찰에 있어서는.자궁상피세포, 질 상피세포, 유선의 변화 그리고 난관 직경의 변화를 관찰하였다. 그 결과 민감도에 있어서 가장 유의적인 변화를 보인 항목은 질 상피세포의 변화였으며, 환경호르몬 물질을 두개씩 혼합하여 처치한 그룹에 있어 단독으로 처치한 그룹과 비교 시 변화의 정도가 심한 것이 일부 관찰 되었으나 통계학적으로 유의성을 가지고 있다고 결론을 내리기 는 힘들었다. 결론적으로 환경호르몬물질간의 생체내에서 상가 혹은 상승작용에 대한 명확한 결과는 도출할 수 없었으나, 환경호르몬물질이 생체내 작용하는 데에 있어서 서로 간에 상승작용을 할 수 있다는 가능성은 충분한 것으로 판단되어진다.

• 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.

• 대한의생명과학회지
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• 제8권2호
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• pp.95-99
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• 2002

Endocrine disruptors are chemicals which can be found in our normal daily life. They can be easily ingested through plastic food containers, pesticides, etc. They include DDT, bisphenol A, benzophenone and phenylphenol, etc. Endocrine disruptor can be very harmful and toxic because it disrupts the normal function of the endogenous endocrine system. It has been reported that endocrine disruptor can cause the fatal strike in reproductive system central nervous system and the other part of the body. We have examined if the growth of lactic acid bacteria could be resistant to the endocrine disruptor. We have used Lactobacillus delbruekii as an experimental strain and benzophenone and phenylphenol for the comparison purpose. Experiments included the evaluation of turbidity, absorbance and actual cell counts. Although Lactobacillus delbruekii showed the higher resistance to benzophenone than phenylphenol it was still resistant to both benzophenone and phenylphenol. Because the experimental concentrations of benzophenone and phenylphenol were so high to compare with the actual concentration we meet in daily life, Lactobacillus delbruekii was considered to be sufficient to survive in the environmental concentration of these endocrine disruptors. This study should contribute to the development of fermented beverage with beneficial effect by lactic acid bacteria.

• 한국독성학회:학술대회논문집
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• 한국독성학회 2003년도 추계학술대회
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• pp.165-165
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• 2003

Phenxoy compounds, 2,4-dichlorophenol acetoxyacid (2,4-D) and 2,4-dichlorophenol (DCP), are widely used as a hormonal herbicide and intermediate for pesticide manufacturing, respectively. We have previously reported the potential of these compounds as androgenic endocrine disruptors using in vivo Hershberger assay and in vitro reporter gene assay.(omitted)

• 여성건강간호학회지
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• 제26권2호
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• pp.171-179
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• 2020

Purpose: This study aimed to investigate the effects of exposure to endocrine disruptors, burnout, and social support from peers on premenstrual syndrome (PMS) in nurses. Methods: This descriptive correlational study was conducted among 122 nurses under the age of 49 working at a university hospital. The participants answered self-report questionnaires. The data were analyzed using the t-test, analysis of variance, Pearson or Spearman correlation coefficients, and hierarchical multiple regression in IBM SPSS version 23.0. Results: The mean age of the nurses was 28.9 years. Of these nurses, 49.2% were working in a general ward, 24.6% in the intensive care unit, 14.8% in the emergency room, and 11.4% in an outpatient department. The explanatory power of the model was 38.3%, and it was statistically significant (F=11.74, p≤.001). Exposure to endocrine disruptors (β=0.32, p<.001) was the most powerful variable affecting PMS, followed by burnout (β=0.27, p=.001), working in the intensive care unit or emergency room (β=0.22, p=.003), family history of PMS (β=0.19, p=.009), and support from coworkers (β=-0.15, p=.043). Conclusion: Based on these findings, it is necessary to develop an intervention program to reduce the symptoms of PMS. Additionally, further studies are needed to develop and evaluate measures to minimize exposure to endocrine disruptors and burnout in order to alleviate PMS among nurses.

• 한국물환경학회지
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• 제28권5호
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• pp.669-675
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• 2012

Recently, there have been active researches regarding endocrine-disrupting chemicals (EDCs). In this study, fifteen small freshwater streams in Cholla-namdo province, South Korea were investigated with respect to the concentration of the endocrine disruptors - Bisphenol A (BPA), styrene monomer (SM), styrene dimer (SD), and styrene trimer (ST) by gas chromatography-mass spectrometry (GC-MS). Measured concentration of the target compounds in the sampled water ranged from

• 대한생식의학회:학술대회논문집
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• 대한불임학회 2005년도 제48차 춘계 학술대회
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• pp.131-132
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• 2005