• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.69-69
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• 2003

Neuroprotective strategies have been appeared to be effective in a variety of stroke models. One of the major focuses has been related to the activities of estrogen. $17\beta$-estradiol valerate(EV) has been reported to exert neuroprotective effects when administered before an ischemic insult. The purpose of this study was to determine whether EV can protect against brain injury via estrogen receptor. Chronic and acute pretreatment can reduce the ischemic damage of focal cerebral ischemia in OVX rat, indicating that EV may be a new therapeutic class of drugs to prevent neuronal damage associated with cerebral ischemia. RNAs were extracted from the hippocampus of ovariectomized female rat with or without EV. Differential gene expression profiles were revealed(Bone morphogenetic protein type 1A receptor, Protein disulphide isomerase, cytochrome bc-1 complex core P, thiol-specific antioxidant protein). RT-PCR and in situ hybridization were used to validate the relative expression pattern obtained by the cDNA array. This Study was supported by the Korea Science and Engineering Foundation(KOSEF) through the Biohealth Products Research Center(BPRC), Inje University, Korea

• Development and Reproduction
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• v.19 no.1
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• pp.33-41
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• 2015

The gonadosomatic index (GSI), gonadal development and changes in hormones in plasma level of the indoor cultured grunt (Hapalogenys nitens) were investigated by histological study from August 2011 to October 2012. The GSI showed similar trends with gonad developmental stages during the culture periods. Changes in plasma level of estradiol-$17{\beta}$ of female H. nitens reached the highest value before the spawning period, and seasonal changes in plasma level of estradiol-$17{\beta}$ were similar in trends of oocyte developments and GSI changes. Testosterone levels of male H. nitens reached the highest value before and after the spent stage. Ovarian developmental stages of H. nitens could be classified into early growing stage, late growing stage, mature stage, ripe and spawning stage, recovery and resting stage. The testicular developmental stages could be divided into growing stage, mature stage, ripe and spent stage, and recovery and resting stage.

• Development and Reproduction
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• v.16 no.4
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• pp.289-294
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• 2012

Gene expressions of cytochrome P4501A (CYP1A), aryl hydrocarbon receptor (AhR) and vitellogenin (Vg) by endocrine disruptors, benzo[${\alpha}$]pyrene (B[a]P) and tributyltin (TBT) were examined in cultured eel hepatocytes which were isolated from eels treated previously with B[a]P (10 mg/kg) or estradiol-$17{\beta}$ (20 mg/kg) in vivo, and the relationship between CYP1A, AhR and Vg genes were studied. When the cultured eel hepatocytes were treated with B[a]P ($10^{-6}-10^{-5}M$) the gene expressions of CYP1A and AhR were enhanced in a concentration-dependent manner. However, when treated with TBT ($10^{-9}-10^{-5}M$) the gene expressions of CYP1A and AhR were suppressed at high concentrations ($10^{-6}-10^{-5}M$), while having no effects at low concentrations ($10^{-9}-10^{-7}M$). Gene expression of Vg was also suppressed by TBT in a concentration-dependent manner in cultured eel hepatocytes which was previously treated in vivo with estradiol-$17{\beta}$.

• Molecular & Cellular Toxicology
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• v.1 no.1
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• pp.52-61
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• 2005

Transcript profiling is a particularly valuable tool in the field of steroid receptor biology, as these receptors are ligand-activated transcription factors and therefore exert their initial effects through altering gene expression in responsive cells. Also, an awareness of endocrine disrupting chemicals (EDCs) and their potential screening methods to identify endocrine activity have been increased. Here we developed an in-house cDNA microarray, named KISTCHIP-400 ver. 1.0, with 416 clones, based on public database and research papers. These clones contained estrogen, androgen, thyroid hormone & receptors, sex hormone signal transduction & regulation, c-fos, c-myc, ps2 gene, metabolism related genes etc. Also, to validate the KISTCHIP-400 ver. 1.0, we investigated gene expression profiles with reference hormones, $10^{8}\;M\;17{\beta}-estradiol,\;10^{-7}\;M\;testosterone\;and\;10^{-7}\;M$ progesterone in MCF-7 cell line. As the results, gene expression profiles of three reference hormones were distinguished from each other with significant and identified 33 $17{\beta}-estradiol$ responsive genes. This study is in first step of validation for KISTCHIP-400 ver. 1.0, as following step transcriptional profile analysis on not only low concentrations of EDCs but suspected EDCs using KISTCHIP-400 ver. 1.0 is processing. Our results indicate that the developed microarray may be a useful laboratory tool for screening EDCs and elucidating endocrine disrupting mechanism.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.4
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• pp.459-465
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• 2015

We tested biomarker systems [enzyme-linked immunosorbent assay (ELISA) and immunochromatography assay (ICG) kits] for the screening of endocrine-disrupting chemicals in contaminated environments using antibodies resulting from $17{\beta}$-Estradiol-induced vitellogenin (Vtg) in the wild scorpion fish Sebastiscus marmoratus. Monoclonal antibodies of two clones (S28 and S15) were used as capture and tracer antibodies for ELISA and ICG assays. ELISA detected Vtg at levels greater than $0.1{\mu}g/mL$, while ICG detected Vtg at levels greater than $1{\mu}g/mL$. However, the ICG system was able to detect antibodies from $17{\beta}$-Estradiol-induced Vtg serum that had been diluted 1,000 times. Our results suggest that previously developed biomarker assays can be used as detection systems to detect known endocrine-disrupting chemicals in contaminated environments, and to measure their activity.

• The Journal of Korea CHUNA Manual Medicine
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• v.1 no.1
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• pp.125-137
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• 2000

the aim of this study was to investigate whether osteoporosis can be advanced after cerebral infarction Of not and role of female sex hormone. all animals were classified 4 groups; group of ovariectomy (OVXgroup) group of cerebral infarction( INF group), group of combination ovariectomy and cerebral infarction(OVX + INF group), naturally intact group for control data (NOR group ). cerebral infarction was made by Chen,s method with some modification and ovariectomy was performed by Wayforth,s method. experimental data was collected at 15 days, 1 month, 3 months and 6months after starting observation. serum 17 ${{\beta}-estradiol\;(E_2)}$ was determined by radioimmunoassay, for comparision of osteoporosis formation, bone density, serum osteocalcin, Serum total calcium and phosphorus, Serum AST Concentration, Serum ALT Concentration, Creatinine Concentration were also calculated. we have found that cerebral ischemia decreases not only the serum concentration of 17 ${{\beta}-estradiol\;(E_2)}$ and inhibits but also the physiologically compensatory function of the ovariectomized rats and that the decreased estrogen concentration followed by cerebral infarction have not produced osteoporosis, regretfully.

• Toxicological Research
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• v.22 no.1
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• pp.15-22
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• 2006

Many of endocrine disrupting chemicals induce effects via interaction with hormone receptors and responsive elements in target cells. We investigated endocrine disrupting effects of some food additives and contaminants including BHA, BHT, ethoxyquin, propionic acid, sorbic acid, benzoic acid, CPM, aflatoxin B1, cadmium chloride, genistein, TCDD and PCBs in yeast transformants expressing human steroid hormone receptors along with steroid responsive elements. The response limit of genetically recombinant yeast to $17{\beta}$-estradiol, testosterone and progesterone was $1{\times}10^{-16},\;1{\times}10^{-12}\;and\;1{\times}10^{-13}M$, respectively. BHT induced weak transcriptional activity in estrogen sensitive yeast, while BHA and sorbic acid interacted weakly with androgen receptor/responsive element. CPM induced transcriptional activities in all types of yeasts sensitive to steroid hormones. Zearalenone and genistein induced high transcriptional activation in estrogen sensitive yeast with relative potencies almost $10^8$ folds lower than $17{\beta}$-estradiol. TCDD induced transcriptional activation weakly in estrogen- and progesterone- sensitive yeasts. This study elucidated that recombinant yeast is a sensitive and high-throughput system and can be used for the direct assessment on chemical interactions with steroid receptors and responsive elements. Also, the present study raises the requirement of evaluation on the endocrine disrupting effects of BHT, BHA, sorbic acid, CPM and TCDD for their transcription activity in yeast screening system though weak in intensity.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2003.11a
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• pp.159-164
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• 2003

Effects of Al on vitellogenin (VTG) and VTG mRNA induction by estradiol-17 $\beta$($E_2$) were examined in primary hepatocyte culture of rainbow trout. Hepatocytes were precultured for 2 days and then E2 ($2{\times}10^{-6}$M) and Al ($10^{-6}-10^{-4}$M) were simultaneously added to the incubation medium. Hepatocytes were cultured for 5 more days. Media and hepatocytes were then analyzed by SDS-PAGE and Northern blotting for VTG and VTG mRNA, respectively. These metal had no appreciable effect on the viability of hepatocytes in culture. However, Al interfered with VTG production and VTG mRNA expression. Al reduced VTG production in a concentration-dependent way and a significant reduction accurred at Al concentrations greater than $5{\times}10^{-5}$M. VTG mRNA expression also decreased with a negative correlation with Al concentration (r＝-0.98). These results suggest that Al inhibit VTG production at the transcriptional level to reduce VTG mRNA expression.

• Korean Journal of Animal Reproduction
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• v.14 no.3
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• pp.223-230
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• 1990

This experiment was carried out to investigate in vitro maturation rate of pig follicular oocytes cultured from 30 to 48hr in TCM 199 supplemented with gonadotropins(FSH, LH) and estradiol-17$\beta$ and in vitro fertilization with ejaculated sperm preincubated in BO medium containing 2mM caffein and development of IVF oocytes. The results obtained in this experiments were as follows ; 1. In addition of hormones, in vitro maturation rate of follicular oocyte increased gradually from 36hr and 74.47% at 48hr in addition of hormones, but there was no differences among in vitro maturation rates after 36hr of culture. 2. Penetration rate of pig oocytes matured in FSH＋LH＋E2 and FSH＋E2 was 71.8%, 71.0% and significantly increased by the addition of hormones. 3. Percentage of developed oocytes was 44.4% for oocytes matured in FSH＋LH＋E2-added medium and 48.7% for oocytes matured in FSH＋E2-added medium, respectively. 4. Two to 16 cells stage embryos were obtained only when pig oocytes matuerd in vitro in hormones-added medium and 72hr after IVF. 5. From present results, it is concluded that gonadotropins and estradiol17$\beta$ can enhance in vitro fertilization and subsequent development as well as in vitro maturation pig follicular oocytes.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.98-98
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• 1993

어류를 이용한 독성 평가방법 및 기작에 관한 연구의 일환으로 여성 호르몬의 일종인 17$\beta$-estradiol (E$_2$)의 갑상선 종양 유발 촉진성을 검증하기 위하여 부화 후 7＋1일 된 암수동체성 어류인 점박이송사리 (Rivulu marmoratu) 를 N-methyl-N'-nitrosourea (MNU) 가 10 ppm 의 농도로 녹아있는 완충 사육수에 2시간 동안 전신 노출시켜서 갑상선 종양의 유도를 촉발 (initiation) 시킨 후, E$_2$가 포함된 시험 사료 (E$_2$ 20 mg/kg diet와 E$_2$ 80 mg/kg diet) 와 이에 대한 대조 사료를 30일간 먹여 사육하였다. 그 후 80일 동안 정상사료인 염전 새우의 유생으로 키우며 매 15일 간격으로 갑상선 종양의 발생 여부를 확인하였다. 발암원 처리 후 E$_2$ 가 함유되지 않은 사료로 사육한 대조군에서는 2.4% 의 개체에서 갑상선 종양이 유도된 반면, E$_2$ 20 mg이 함유된 사료를 투여한 실험군에서의 갑상선종양 유발율은 34%로, 대조군에서 보다 14배 정도 증가하였다 (p<0.01). MNU 처리 후 E$_2$ 60 mg/kg 사료를 먹인 실험군에서의 갑상선 종양 유발율은 E$_2$ 20 mg/kg 사료를 먹인 실험군에 비하여 발암 잠재기 (latency)가 15일 정도 단축되었다. 본 실험의 결과는 E$_2$가 다단계 (multistage)로 이루어진 갑상선 종양 발생기작에 발암 촉진제로써의 역할을 한다는 것을 입증할 뿐만 아니라, 본 종이 갑상선 종양의 발생 및 촉진기작을 연구하는데 매우 적합한 실험동물 모델임을 보여준다.