• 한국환경보건학회지
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• 제33권6호
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• pp.513-516
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• 2007

This investigation was intended to find out the estrogenic effect of chlortetracycline (CTC) on vitellogenin induction in adult male Japanese medaka (Oryzias latipes). Vitellogenin (Vtg) produced in male fish has been used to as one of a biomarker of endocrine disrupters. The positive control was $17{\beta}-estradiol$ (E2) that induced Vtg in male fish. As a result, male and female fish were exposed to 0.1, 1, 10 and 100 ppm of CTC. Western blot results showed approximately 205 kDa, that is similar to myosin at high molecular weight range Sigma maker. Vtg band was showed fainted to 10 and 100ppm for chlortetracycline. Vtg concentration of CTC was qunatified by total protein quantification and ELISA. Exposure of the male fish to CTC of 0.1, 1, 10 and 100 ppm produced Vtg concentrations of 0.24, 0.12, 7.61 and 40.02%o, respectively, that value was elevated than control male fish (0.14%o). CTC exerted as a Vtg inducer in male fish from 10 ppm, but it was a reducer in female fish from 0.1 ppm level. The results say that vitellogenin induction patterns alter in male medaka treated with CTC, and that CTC may caused endocrine disruption in fish.

• Toxicological Research
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• 제26권4호
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• pp.301-313
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• 2010

Growth promoters including hormonal substances and antibiotics are used legally and illegally in food producing animals for the growth promotion of livestock animals. Hormonal substances still under debate in terms of their human health impacts are estradiol-$17\beta$, progesterone, testosterone, zeranol, trenbolone, and melengestrol acetate (MGA). Many of the risk assessment results of natural steroid hormones have presented negligible impacts when they are used under good veterinary practices. For synthetic hormonelike substances, ADIs and MRLs have been established for food safety along with the approval of animal treatment. Small amounts of antibiotics added to feedstuff present growth promotion effects via the prevention of infectious diseases at doses lower than therapeutic dose. The induction of antimicrobial resistant bacteria and the disruption of normal human intestinal flora are major concerns in terms of human health impact. Regulatory guidance such as ADIs and MRLs fully reflect the impact on human gastrointestinal microflora. However, before deciding on any risk management options, risk assessments of antimicrobial resistance require large-scale evidence regarding the relationship between antimicrobial use in food-producing animals and the occurrence of antimicrobial resistance in human pathogens. In this article, the risk profiles of hormonal and antibacterial growth promoters are provided based on recent toxicity and human exposure information, and recommendations for risk management to prevent human health impacts by the use of growth promoters are also presented.

• Molecular & Cellular Toxicology
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• 제2권2호
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• pp.106-113
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• 2006

Phthalate analogues are a plasticizer and solvent used in industry. Phthalates were classified in the category of "suspected" endocrine disruptors. The purpose of our study was to screen and elucidate the endocrine disrupting activity of seven phthalate analogues. E-screen assay was performed in MCF-7 human breast cancer cells with seven phthalate analogues. In this cell proliferation assay, benzyl butyl phthalate (BBP) and dibutyl phthalate (DBP) showed high estrogenic activity. Their relative proliferation efficiencies (RPE) were 109 and 106%, respectively. In vitro estrogen receptor (ER) binding assay, BBP, di-n-octyl phthalate (DOP) and dinonyl phthalate (DNP) showed weak relative binding affinity (RBA: 0.02%) compared to $17{\beta}-estradiol\;(E2)$ (RBA: 100%). In uterotrophic assay, E2 produced a significant increase, whereas four tested phthalate analogues had potential estrogenic effects in vitro did not increased in uterus weight in immature rats. From these results, we demonstrated that phthalate analogues exhibit weak estrogenic activity in vitro assays at high concentrations. Although phthalates induced an increase in MCF-7 cell proliferation by an estrogenic effect, they could not induce a uterus weight increase in vivo. From these, we may suggest that these phthalate analogues are easily metabolized to inactive forms in vivo. Further investigation in other in vitro and in vivo experimental systems might be required.

• 한국수산과학회지
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• 제28권6호
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• pp.753-760
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• 1995

This study was conducted to determine the serum vitellogenin (VTG) concentration changes during the ovulation period in elkhorn sculpin, Alcichthys alcicornis. The results of sepacryl S-300 showed that the molecular weight of VTG could be 380,000. SDS-polyacrylamide gel electrophoresis (SDS-PAGE) analysis may indicate that the purified VTG consists of three subunits with molecular weights of 180,000, 118,000 and 85,000, respectively. Yolk protein purified from the egg extracts was eluted on an equilibrated sephacryl S-300 column, and its molecular weight was estimated 250,000. The precipitation lines of the female serum against the antiserum of the egg extracts were fused completely by immunoelectrophoresis and immunodiffusion analysis. VTG was detected in the serum, and hepatocytes from males injected with $17\beta-estradiol\;(E_2).$ Furthermore, VTG was immunochemically similar to yolk proteins. The concentration of VTG was high before ovulation $(9.80\pm0.81-11.02\pm0.09 mg/ml),$ and then decreased rapidly after ovulation $(less\;than\;6.19\pm0.59 mg/ml).$ This study suggested that VTG was synthesized in the liver by the action of $E_2$ and released to blood, and then incorporated into oocytes.

• Fisheries and Aquatic Sciences
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• 제14권4호
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• pp.355-361
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• 2011

Effects of aluminum (Al) on plasma vitellogenin (VTG), alkaline-labile phosphorus (ALPP), calcium (Ca), glutamate pyruvate transaminase (GPT), the hepatosomatic index (HSI), and hepatic Al concentration were examined in estradiol-$17{\beta}$ ($E_2$)-administered immature rockfish Sebastes schlegeli. Fish were injected intraperitoneally with $E_2$ (5 mg/kg body weight [BW]) and/or Al (0, 0.1, 1, 5, and 10 mg/kg BW) and plasma and liver samples were extracted 7 days later. After sodium dodecyl sulfate polyacrylamide gel electrophoresis, the relative amount of VTG was determined by integrated optical density. VTG accounted for 23.6% of the total proteins in the control group, but this value decreased with increasing Al administration. Al reduced the concentrations of ALPP and Ca in a concentration-dependent manner and significant reduction occurred at Al concentrations greater than 5 mg/kg. The concentration of GPT increased in a concentration-dependent manner in all Al-administered rockfish. The concentrations of Al in the liver also increased, and HSI was decreased, in a concentration-dependent manner. These results suggest that Al inhibits $E_2$-induced VTG production by being toxic to hepatocytes in marine fish.

• 한국가축번식학회지
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• 제18권1호
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• pp.47-54
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• 1994

The objective of this study was to produce Korean native calves following transfer of in vitro matured, fertilized and cultured embryos into Holstein cows. The ovaries of Korean native cows or heifers were obtained from an abattoir and kept on 25 to 28$^{\circ}C$ and transported to laboratory within 2 hrs. The oocytes were matured in vitro (IVM) for 24 hrs in TCM-199 supplemented with 35$\mu\textrm{g}$/ml FSH, 10$\mu\textrm{g}$/ml LH, 1$\mu\textrm{g}$/ml estradiol-17$\beta$ and granulosa cells at 39$^{\circ}C$ under 5% CO2 in air. They were fertilized in vitro (IVF) by epididymal spermatozoa treated with heparin for 24 hrs., and then the zygotes were co-cultured in vitro (IVC) with bovine oviductal epithelial cells for 7 to 9 days. Late morulae and blastocysts produced in vitro were nonsurgically transferred to recipient cows by unilaterial. Recipients were monitored for estrus and for pegnancy by rectal plapation in 60 days after embryo transfer. One of them was pregnant to term and produced a female weighing 42.5kg at birth.

• Reproductive and Developmental Biology
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• 제35권4호
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• pp.519-525
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• 2011

Growth hormone (GH) is obligatory for growth and development. But, there is controversy on the GH effect about reproductive processes of sexual differentiation, pubertal maturation, gonadal steroidogenesis, gametogenesis and ovulation. This study was conducted to investigate the effect of GH on estrus, ovulation and embryo implantation. The results obtained were as follows. GH stimulated to increase estrus rate (p<0.05), pregnancy rate (p<0.05), and total fetus number in mice treated for superovulation. Also, the correlation between GH and steroids, E2 and P4, at peri-estrus stage/ peri-ovulation stage/ peri-implantation stage of the superovulation-induced mice was examined. Consequently, GH co-injected with PMSG especially increased P4 level (p<0.05) at peri-estrus stage of superovulationinduced mice. In conclusion, GH co-treatment in superovulation system boosted the rate of estrus, pregnancy and total fetus by increasing progesterone level at peri-estrus stage of superovulation-induced mice.

• 대한수의학회지
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• 제32권1호
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• pp.135-142
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• 1992

This experiment was carried out to establish an effective technique of in vitro maturation of porcine follicular oocytes. Porcine ovaries were collected from an abbatoir and delivered to the laboratory in phosphate buffered saline in an hour. Immatured follicular oocytes were collected from the ovaries and divided into groups by the size of follicles and by the attachment of granulosa cells. The follicular oocytes were cultured in m-KRB solution supplemented with FCS(10%), follicular fluid(10%) or hormones of PMSG(10IU/ml), hCG(10IU/ml ) and $estradiol-17{\beta}(1{\mu}g/ml)$ for 48 hours at $39^{\circ}C$ under an atmosphere of 5% $CO_2$ in air. The results are as follows ; 1. The mean recoveration rate of follicular oocytes was 61.8%. 2. The maturation rate was significantly(p<0.05) higher when the oocytes were collected from large-sized follicles and under good state of granulosa cell attachment. 3. The maturation rate was significantly(p<0.01) promoted when the follicular oocytes were cultured in m-KRB solution supplemented with follicular fluid(74.8%) or hormones and fetal calf serum(70.6%).

• Food Science and Biotechnology
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• 제18권3호
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• pp.689-693
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• 2009

Germination is well-known to enhance the digestibility, functionality, and palatability of plant seeds. To examine the functionality of germinated-safflower seed (GSS), proliferative and differentiative effects of GSS extract on the mouse calvarial bone cells were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolinbromide (MTT) assay and alkaline phosphatase activity, respectively. Water extract of GSS increased dose-dependently proliferative and differentiative effects on calvarial bone cell, and its effects were stronger than those of ungerminated-safflower seeds (UGSS) extract. One major component was isolated from GSS extract by a series of purification procedure of solvent fractionation, Diaion HP-20, and Sephadex LH-20 column chromatographies. Its chemical structure was identified as trachelogenin (TC) by nuclear magnetic resonance (NMR) and mass spectrometry (MS) spectral analysis. Trachelogenin showed significant proliferative (125.7%) and differentiative (132.1%) effects on calvarial bone cells at $10^{-8}M$, and its effects were significantly higher than those of $17{\beta}-estradiol\;(E_2)$. TC was found to be a major active compound responsible for high proliferative and differentative effects of the water extract of GSS. Therefore, these results suggest that TC in GSS may be useful as potential therapeutic agent for the prevention and treatment of bone loss.

• Environmental Analysis Health and Toxicology
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• 제17권3호
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• pp.239-243
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• 2002

Changes of plasma vitellogenin (VTG) and glutamate pyruvate transaminase (GPT) were examined for determining whether hepatocyte was damaged during the process of VTG induction in the juvenile rockfish, Sebastes schlegeli exposed to exogenous estrogen (estradiol-l7$\beta$, E$_2$). Rockfishes were intraperitoneally injected with E$_2$(5 mg/kg B.W.) in 70% ethanol and plasma sampling were extracted at 0, 1, 3, 6, 9, 12, 15 days af-ter E$_2$administration. VTG and GPT were then analyzed by SDS -PAGE and Reitman -Frankel method, respectively. VTG band was detected at a molecular weight position of 175 kDa on Day 3 after E$_2$administration. This band became more distinct at 6 days, but its was gradually thinned with time -course, and not detected at 15 days. GPT was suddenly increased at 1 days after 22 administration and highest GPT was detected at 3 days. However. GPT was gradually decreased with time -course as the change of VTG. These results suggest that the process of VTG induction by exogenous E$_2$damage to hepatocyte, and plasma GPT was temporarily increased in the juvenile rockfish.