• 제목/요약/키워드: Environmental hormone

검색결과 286건 처리시간 0.02초

메틸수은 노출이 흰쥐의 태반 효율과 태아 성장에 미치는 영향 (Effects of Methyl Mercury Exposure on Placental Efficiency and Fetal Growth Retardation in Rats)

  • 이채관
    • 한국환경보건학회지
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    • 제46권4호
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    • pp.368-375
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    • 2020
  • Objectives: Some animal studies have reported that methyl mercury causes developmental toxicities such as placental and fetal weight loss, but the mechanism is still unclear. This study aimed to investigate the developmental toxicities of methyl mercury, focusing on placental endocrine function and fetal growth retardation in rats. Methods: Positively same-time-mated female Sprague-Dawley rats were purchased on gestational day (GD) eight and treated with 0, 5, 10 and 20 ppm of methyl mercury (n=5) dissolved in tap water from GD eight through 19. During treatment, the drinking water (methyl mercury) intake and body weight of each pregnant rat was measured daily. On day 19, caesarean sections were performed and blood samples were collected. Developmental data such as placental and fetal weights, fetus numbers, and placental efficiency (fetal weight/placental weight) were also collected. Placental prolactin-growth hormone (PRL-GH) family, such as placental lactogen (PL) -Iv, II, and prolactin-like protein (PLP) -B, levels in serum were analyzed by ELISA. Also, placental tissues were assigned to histochemistry. Results: The mean cumulative methyl mercury exposure for the 5, 10, and 20 ppm groups were 2.37, 4.63, and 9.66 mg, respectively. The mean daily exposure of the 5, 10, and 20 ppm groups were 0.24, 0.47, and 0.97 mg, respectively. Maternal body weight increased in accordance with GD. There was no significant difference in weight gain among the experimental groups. Histopathologic changes were not observed in placental tissues among the experimental groups. However, mean placental and fetal weights were lower in the 10 and 20 ppm exposed groups compared to the control. Placental efficiency was also lower in the 10 and 20 ppm exposed groups compared to the control. Serum PL-Iv and II levels were lower in the 10 and 20 ppm exposed groups than the control, in accordance with the changing pattern of placental and fetal weights and placental efficiency. Conclusion: The inhibitory effects of methyl mercury on the serum levels of placental PRL-GH family such as PL-Iv and II may be secondary leads to the reduction of placental efficiency and fetal growth retardation in rats.

The Effects of 20-hydroxyecdysone in Drosophila Kc Cells on the Ecdysteroidosis

  • Hwang, Seong-Hee;Kim, Pan-Gyi
    • 한국환경보건학회지
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    • 제28권4호
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    • pp.1-5
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    • 2002
  • Drosophila Kc cells are ecdysone-responsive : hormone treatment leads rapidly to increased synthesis of several ecdysone-inducible polypeptides (EIPs) and to commitment to eventual proloferative arrest. Later the treated cells undergo morphological transformation, cease to proliferate and to grow. These responses have proven useful as models for studying ecdysone action and environmental endocrine disrupting actions. In this study, we used 20-HE to check out the Kc cells properties to the ecdysone and this properties will be applied to the environmental chemicals to find out the endocrine disrupting action in ecosystem. The cell counts of cultures harvested after 3 days' growth in the presence of 20-hydroxyecdysone. In Kc cell cultures, there were statistically significant different from control cells at 20HE 10/sup 7/-10/sup 5/. The morphological effects of all the hormones were similar, differing only in the dose level at which they were initiated.

골든 햄스터의 생식내분비계에 미치는 멜라토닌의 영향 (Effects of Melatonin on the Reproductive Endocrine System in Male Golden Hamsters)

  • 최돈찬;우대균;임시내
    • 환경생물
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    • 제20권3호
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    • pp.224-231
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    • 2002
  • 광주기(하루 중 빛의 길이)는 골든 햄스터의 생식을 조절하는 주된 요인이다. 광주기 정보는 멜라토닌을 통하여 생식 내분비계로 전달된다. 따라서 멜라토닌이 생식에 미치는 효과를 여러 광주기에 노출시킨 햄스터에서 조사하였다. 단주기(하루 중 12시간 이하의 조명)에 노출시킨 동물들과 저녁에 멜라토닌을 주사한 동물들의 정소 무게는 현저하게 줄어들었으나, 장주기 (하루 중 12.5시간 이상의 조명)에 유지된 동물과 오전에 멜라토닌을 투여한 동물들의 정소 무게는 줄어들지 않았다. 퇴화된 정소를 조직학적으로 조사한 결과, 세정관 직경이 감소되었고, 세정관내 세포수가 두드러지게 줄어들었다. 또한 생식 능력이 퇴화된 동물의 혈중 여포자극호르몬과 황체호르몬의 수준도 생식 능력을 보유하고 있는 동물에 비해 뚜렷하게 감소하였다. 멜라토닌 수용체가 역전사 polymerase chain reaction으로 동정되었고 조직특이성 또한 조사하였다. 동정된 멜라토닌 수용체는 309염기였으며, 시상하부와 뇌하수체를 포함하는 다양한 장기에서 발현되었다. 생식을 조절하는 핵심 물질인 gonadotropin releasing hormone (GnRH) 유전자의 발현 또한 동정되었다. 그러나 멜라토닌 처리와 광주기 처리는 GnRH유전자 발현에 영향을 미치지 않았다. 종합하면, 광주기의 효과는 멜리토닌을 경유하여 발휘되며, 멜라토닌은 GnRH유전자의 발현보다는, 생성된 GnRH의 분비에 영향을 미쳐 생식내분비계에 간접적으로 작용함을 알 수 있었다.

Structure and Function of the Phytochromes: Light Regulation of Plant Growth and Development

  • Park, Chung-Mo;Song, Pill-Soon
    • Journal of Photoscience
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    • 제10권1호
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    • pp.157-164
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    • 2003
  • Light exerts two primary roles in plant growth and development. Plants acquire all biochemical energy required for growth and propagation solely from light energy via photosynthesis. In addition, light serves as a medium through which plants recognize environmental fluctuations, such as photoperiod and presence of neighboring animals and plants. Plants therefore constantly monitor the direction, intensity, duration, and wavelength of environmental light and integrate these light signals into the intrinsic regulatory programs to achieve an optimized growth in a given light condition. Although light regulates all aspects of plant growth and developmental aspects, the molecular mechanisms and signaling cascades involved have not been well established until recently. However, recent advances in genetic tools and plant transformation techniques greatly facilitated the elucidation of molecular events in plant photomorphogenesis. This mini-review summarizes the gist of recent findings in deetiolation and suppression of shade avoidance response as classic examples of the phytochrome-mediated photomorphogenesis.

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Effect of DDT on Testosterone Production by Modulator Aromatase (CYP 19) in R2C

  • Lee, Kyung-Jin;Lee, Jong-Bin;Jeong, Hye-Gwang
    • 환경생물
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    • 제21권3호
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    • pp.308-312
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    • 2003
  • Various pesticides known or suspected to interfere with steroid hormone function were screened toy effects in leydig cells on catalytic activity and mRNA expression of aromatase. Dichlorodiphenyltrichloroethane (DDT) is a widespread environmental pollutant. In this study, we investigated the effect of DDT on testosterone production through aromatase activity and its molecular mechanism in testicular leydig cell, R2C by using radioimmunoassay (RIA). As the results, the potent leydig: cell activator LH increased testosterone production compared to the control. DDT exposure significantly decreased testosterone production in R2C cell. In addition, DDT was found to increase aromatase gene expression and activity in R2C cell in a dose dependent manner. In order to assess whether the suppressive effects of DDT on LH-inducible testosterone (T) production might be influenced by the ER, ICI 182.780 was used, and it was found that these inhibitory effects of DDT were antagonized by ICI 182.780, implying that the estrogen receptor (ER) mediates the suppressive effects of DDT. Furthermore, the inducible effects of DDT on aromatase gene expression might be influenced by the ER, ICI 182.780 was used, and it was found that these enhancing effects of DDT were antagonized by ICI 182.780, implying that the ER mediates the inducible effects of DDT. Our results indicated that DDT inhibition of luteinizing hormone (LH) -inducible T production in R2C cell is mediated through aromatase. However, the precise mechanisms by which DDT enhance in R2C cell remains unknown. The current study suggests the possibility that DDT might act as a modulator aromatase gene transcription.

Enzymatic characterization and Expression of 1-aminocycloprophane-1-carboxlyate deaminase from the rhizobacterium Pseudomonas flourescens

  • Lee, Gun-Woong;Ju, Jae-Eun;Kim, Hae-Min;Lee, Si-Nae;Chae, Jong-Chan;Lee, Yong-Hoon;Oh, Byung-Taek;Soh, Byoung-Yul
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2010년도 정기총회 및 춘계학술발표회
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    • pp.17-17
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    • 2010
  • Ethylene, known as a stress hormone regulate wide developmental processes including germination, root hair initiation, root and shoot primordial formation and elongation, leaf and flower senescence and abscission, fruit ripening. The acceleration of ethylene biosynthesis in plant associated with environmental and biological stresses. 1-Aminocycloprophane-1-carboxlyate deaminase(ACCD) is an enzyme that cleaves ACC into and ammonia, a precursor of the plant hormone ethylene. Plant growth-promoting rhizobacteria (PGPR) having ACCD can decrease endogenous ACC level of tissue, resulting in reduced production of ethylene in plants. ACC deaminse was a key enzyme for protect stressed plants from injurious effects of ethylene. ACCD gene was encoded from Pseudomonas flourescens, PGPR and was cloned in Escherichia coli. We expressed the recombinant ACCD(rACCD) containing 357 amino acids with molecular weight 39 kDa that revealed by SDS-PAGE and western blot. The rACCD was purified by Ni-NTA purification system. The active form of rACCD having enzyme activity converted ACC to a-ketobutyrate. The optimal pH for ACC deaminase activity was pH 8.5, but no activity below pH 7.0 and a less severe tapering activity at base condition resulting in loss of activity at over pH 11. The optimal temperature of the enzyme was $30^{\circ}$ and a slightly less severe tapering activity at 15 - 30$^{\circ}$, but no activity over $35^{\circ}$. P. flourescens ACC deaminase has a highly conserved residue that plays in allowing substrate accessibility to the active sites. The enzymatic properties of this rACCD will provide an important reference for analysis of newly isolated ACCD and identification of newly isolated PGPR containing ACCD.

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Effects of acute di-n-butyl phthalate administration on oxidative stress parameters

  • Choi, Dal-Woong;Kim, Young-Hwan;Sohn, Jong-Ryeul;Moon, Kyung-Hwan;Byeon, Sang-Hoon
    • 한국환경보건학회:학술대회논문집
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    • 한국환경보건학회 2004년도 International Conference Global Environmental Problems and their Health Consequences
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    • pp.178-181
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    • 2004
  • Di-n-butyl phthalate (DBP) is used extensively in the plastic industry and has been known as an environmental hormone (endocrine disruptor). Present study was undertaken to examine whether DBP can induce oxidative stress in mice. In this study, oxidative stress was measured in terms of the modification of lipid peroxidation and gamma-glutamyltranspeptidase (${\gamma}-GT$) activity. The activity of ${\gamma}-GT$, the level of lipid peroxidation and serum toxicity index were measured in male ICR mice after treatment with DBP (5 g/kg, po). Administration of DBP was found to significantly increase the level of lipid peroxidation approximately 2 fold in liver. The activity of ${\gamma}-GT$ in the liver of DBP-exposed animals was also increased approximately 2.5 fold. However, DBP did not alter the parameters for hepatotoxicity and nephrotoxicity such as alanine aminotransferase (ALT), aspartate aminotransferase (AST) and creatinine. These results indicate that DBP can induce oxidative stress in mice. The ${\gamma}-GT$ activity is considered to be increased as one of the adaptive defense mechanisms to oxidative stress induced by DBP.

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Assessment of In Vitro Assay System for Thyroid Hormone Disruptors Using Rat Pituitary GH3 Cells

  • Kim, Hee-Jin;Park, Hae-Young;Kim, Jeong-A;Kang, Il-Hyun;Kim, Tae-Sung;Han, Soon-Young;Kang, Tae-Seok;Park, Kui-Lea;Kim, Hyung-Sik
    • Toxicological Research
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    • 제22권4호
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    • pp.307-313
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    • 2006
  • The development of in vitro assays has been recommended to screening and testing the potential endocrine disruptors (EDs). These assay systems focus only on identifying the estrogenic or antiestrogenic activity of EDs, whereas a few studies have been carried out to screen the thyroid hormone (TH) disruptors. The aim of this study was to evaluate a test system to detect TH disruptors using rat pituitary tumor $GH_3$ cells. The test system is based on the TH-dependent increase in growth rate. As expected, L-3,5,3-triiodothyronine ($(T_3)$ markedly induced a morphological change in $GH_3$ cells from flattened fibroblastic types to rounded or spindle-shaped types. $T_3$ stimulated $GH_3$ cell growth in a dose-dependent manner with the maximum growth-stimulating effect being observed at a concentration $1{\times}10^9M$. In addition, $T_3$ increased the release of growth hormone and prolactin into the medium of the $GH_3$ cells culture. Using this assay system, the TH-disrupting activities of bisphenol A (BPA) and its related compounds were examined. BPA, dimethy/bisphenol A (DMBPA), and TCI-EP significantly enhanced the growth of $GH_3$ cells in the range of $1{\times}10^{-5}M\;to\;1{\times}10^{-6}M$ concentrations. In conclusion, this in vitro assay system might be useful for identifying potential TH disruptors. However, this method will require further evaluation and standardization before it can be used as a broad-based screening tool.

Japanese medaka에 있어 Quercetin의 난자성숙 저해에 대한 조직병리학적 연구 (Histopathological Study on Inhibition of Oogenesis by Quercetin in Japanese medaka (Oryzias latipes))

  • 황갑수
    • Environmental Analysis Health and Toxicology
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    • 제14권1_2호
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    • pp.55-63
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    • 1999
  • Endocrine disrupting chemicals probably cause the cytological or/and morphological changes of germinal cells in gonad. Accordingly, this study was aimed to make sure that the effect of hormone-mimicking chemicals on gonad morphology such as decrease of germinal cells, inhibition of cellular maturation and change in the ratio of germinal cells in the different developmental phase can be observed by histopathological procedures and can be a useful bio-indicator for the evaluation of endocrine disruption by environmental chemicals. In this experiment, female Japanese medaka were exposured to quercetin, a phytoestrogen, at the concentration of 100 $\mu\textrm{g}$/L. quercetin showed the significant decrease in the number and rate of vitellogenic follicular oocytes in the treated group for 4 and 6 weeks. The weak development of yolk could be also observed. We could conclude that quercetin has anti-estrogenic or androgen-like potency by exerting the inhibition effect on oogenesis in fish female- gonad. From the result of this study, the applied methods and techniques can be evaluated to be a useful biomonitoring means for water pollution, expecting a good result of the subsequent study on apoptosis.

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Estrogenic Activity Assessment of Alkylphenolic chemicals using in vitro assays : III. Rcombinant Yeast Transcriptional Assay

  • Park, Hyo-Joung;Lee, Ho-Ja;Park, Kyunghee;Ryu, Jae-Chun
    • 한국환경독성학회:학술대회논문집
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    • 한국환경독성학회 2001년도 춘계심포지움 및 학술발표회
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    • pp.127-127
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    • 2001
  • There is a concern that chemicals in our environment are affecting human health by disrupting a normal endocrine function. Much of the concern has focused on chemicals that can interact directly with steroid hormone receptors. The ability of certain man-made chemicals to mimic the effects of natural steroid hormones and their potential to disrupt the delicate balance of the endocrine system in animals are of increasing concern. (omitted)

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