• 한국수산과학회지
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• 제56권3호
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• pp.309-314
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• 2023

Shark populations are constantly decreasing owing to environmental destruction and overfishing; thus, sharks are now at risk of extinction, with 30.5% of species classified as endangered on the International Union for Conservation of Nature's Red List. Sharks are apex predators and keystone species in balancing the marine food chain; their extinction would create an imbalance in the entire marine ecosystem. Assisted reproductive technology is a last resort for protecting animals facing extinction. Here, as a proactive effort toward building a hormone-induced artificial insemination protocol for endangered wild sharks, we identified the possibility of germ cell maturation by administration of GnRH, a commercially produced synthetic salmon gonadotropin-releasing hormone, and calculated its optimum dosage and injection timing. The experiment was conducted on one shark species, Chiloscyllium plagiosum. Injections were administered in 24 h intervals to C. plagiosum females, and 0.2 mL/kg+0.2 mL/kg were the optimal doses. These doses effectively induced maturation and, and ovulation, and oocyte release. Our results confirm that GnRH is a suitable tool for shark hormone-induced artificial insemination and indicate that this method may facilitate the conservation of endangered shark species.

• BMB Reports
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• 제31권5호
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• pp.419-426
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• 1998

The nuclear hormone receptor superfamily currently includes approximately equal numbers of conventional receptors and orphan receptors, which do not have known ligands. Here, we review recent progress from this laboratory on three orphans, two of which are moving from orphan to conventional receptor status. Perhaps the most unusual is CAR, which is a constitutive transactivator in the absence of ligands but becomes transcriptionally inactive in the presence of its ligands, which are androgen metabolites. The response of CAR to its ligands is thus opposite to that of the conventional receptor paradigm. RIP14 (also known as FXR) is activated by both all-trans retinoic acid and a synthetic retinoid previously thought to specifically target the retinoic acid receptors (RARs), and thus appears to be a novel retinoid receptor. Finally, SHP is a novel orphan that lacks a DNA binding domain and interacts with a number of other receptor superfamily members. While it generally inhibits its targets, including CAR, the retinoid X receptor (RXR), and the estrogen receptor (ER), it stimulates transactivation by the orphan SF-1.

• 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.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.346.1-346.1
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• 2002

FXR (farnesoid X-activated receptor) is a member of nuclear steroid hormone receptor superfamily and especially a orphan receptor, which are able to control mevalonate pathway upon activation by binding of the specific ligands. We. have launched our study for development of FXR specific ligands getting on in lead discovery. A promising lead stilbene analog was obtained through the screening of a set of library compounds which was previously targeted for other nuclear receptors. And then synthetic modilication of the lead was perfoumde. In addition. fishing a new pharmacophore was fried by UNITT aearch. which brought new structural features.

• 대한핵의학회지
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• 제14권1호
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• pp.1-8
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• 1980

Serum TSH levels were measured by radioimmunoassay before and after intravenous administration of synthetic thyrotropin-releasing hormone (TRH) to 15 normal subjects and 55 patients with primary thyroid disease (14 patients with euthyroidism, 24 patients with thyrotoxicosis and 17 patients with hypothyroidism) to evaluate pituitary TSH reserve and its diagnostic availability. The observed results were as follows. 1. In normal subjects, serum TSH responses to synthetic TRH were $3.2{\pm}1.0$ at 0min (baseline TSH level), $8.0{\pm}4.0$ at 10min, $11.7{\pm}5.0$ at 20min, $13.7{\pm}7.1$ at 30min, $9.7{\pm}5.0$ at 60min., $5.2{\pm}2.0$ at 120min. and $3.6{\pm}0.4{\mu}U/ml$ at 180 min. Serum TSH peaked at $20{\sim}30$ minutes and returned nearly to baseline at 180minutes. 2. In euthyroid group, serum TSH responses to synthetic TRH were $3.3{\pm}1.6$ at 0min, $8.6{\pm}8.0$ at 10min, $10.9{\pm}8.5$ at 20min, $12.5{\pm}8.4$ at 30min, $9.0{\pm}5.9$ at 60min, $5.6{\pm}2.6$ at 120min and $3.5{\pm}1.3{\mu}U/ml$ at 180min. No significant difference revealed between euthyroid group and normal subjects (p>0.05). 3. In hyperthyroid group, serum TSH responses to synthetic TRH were $1.5{\pm}0.6$ at 0min, $2.2{\pm}0.8$ at 10min., $2.3{\pm}1.0$ at 20min., $2.4{\pm}1.5$ at 30min., $2.1{\pm}1.1$ at 60min., $1.9{\pm}0.2$ at 120min. and $1.5{\pm}0.8{\mu}U/ml$ at 180min., No response to TRH showed. 4. In hypothyroid group, mean values of serum TSH response to synthetic TRH were 42.0 at 0min., 60.6 at 10min., 124.8 at 20min., 123.0 at 30min., 101.6 at 60min., 64.3 at 120min. and $15.5{\mu}U/ml$ at 180 min., Patients with primary hypothyroidism showed an exaggerated TSH response to synthetic TRH despite their high basal TSH. 5. Side effects attending synthetic TRH administration were transient nausea (59.0%), desire to micturate (59.0%), feeling of flushing(19.7%), dizziness (45.9%), metallic taste (9.8%) and headache (19.7%). Any side effect didn't show in 16.4%. These symptoms began almost immediately after TRH intravenous injection and lasted several minutes, and not related to dose or response in the person experiencing it.

• Applied Biological Chemistry
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• 제49권3호
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• pp.196-201
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• 2006

Vitellogenin은 어류의 난황 단백질의 전구체 물질로서 암컷 혈청에서 발견되는 단백질이며, 외부에서 에스트로겐이나 내분비계장애물질에 노출된 경우에는 수컷이나 미성숙한 암컷에서도 이의 합성이 촉진되는 것으로 보고되었다. 따라서 수컷에서 유도되는 vitellogenin은 외인성 에스트로겐 물질에 노출되었음을 암시하는 중요한 지표로 인정되고 있다. Vitellogenin에 대한 항체를 생산하기 위하여 잉어의 vitellogenin 서열 중의 일부분에 대한 peptide를 합성한 후 그 합성 peptide에 대한 항체를 제작하였다. 그리고 $17{\beta}$-estradiol을 주입한 잉어의 혈청에서 DE-52 이온 교환 크로마토그래피를 사용하여 vitellogenin을 정제한 후 이에 대한 항체를 제작하였다. 본 연구에서는 상기의 합성 vitellogenin peptide에 대하여 제작한 다클론 항체와 vitellogenin 단백질에 대한 다클론 항체가 추후 에스트로겐의 지표로 사용될 수 있는 지를 조사하고자 항체의 반응성을 조사하였다. 정제하여 얻은 vitellogenin에 대한 다클론 항체는 Western blotting 시 $17{\beta}$-estradiol을 주입한 잉어의 혈청과 암컷 잉어의 혈청에 있는 vitellogenin과 반응한 반면에 vitellogenin peptide에 대한 다클론 항체는 이들과 반응하지 않았다. 이는 공유결합적으로 많은 변형이 일어난 vitellogenin 단백질은 vitellogenin 합성 펩타이드에 대한 항체로는 검출되지 않음을 나타낸다.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.207.3-208
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• 2003

Peroxisome proliferator-activated receptor (PPAR), a member of the nuclear hormone receptor superfamily, is a transcription factor activated by specific natural or synthetic ligands. It is involved in various cellular processes including adipogenesis, inflammation, cell cycle progression and carcinogenesis. Here, we report the production and characterization of a PPARgamma subtype-specific monoclonal antibody P${\gamma}$ 48.34A, which was raised against full-length human PPARgamma protein. (omitted)

• Toxicological Research
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• 제26권4호
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• pp.237-243
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• 2010

Endocrine disrupting chemicals (EDCs) have been shown to interfere with physiological systems, i.e., adversely affecting hormone balance (endocrine system), or disrupting normal function, in the female and male reproductive organs. Although endocrine disruption is a global concern for human health, its impact and significance and the screening strategy for detecting these synthetic or man-made chemicals are not clearly understood in female and male reproductive functions. Thus, in this review, we summarize the interference of environmental EDCs on reproductive development and function, and toxicological mechanism(s) of EDCs in in vitro and in vivo models of male and female reproductive system. In addition, this review highlights the effect of exposure to multiple EDCs on reproductive functions, and brings attention to their toxicological mechanism(s) through estrogen receptors.

• Journal of Plant Biology
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• 제25권4호
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• pp.161-168
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• 1982

The activities of auxins and cytokinins have been examined in the growth of callus tissue derived from Phaseolus vulgaris L. cv. Damyang. The synthetic auxin, picloram was the most effective in promoting callus growth and the range of effective concentrations (0.1$\mu{M}$ to 32$\mu{M}$) was broad. 2, 4-D also enhanced callus growth at the optimal concentration of 3.2$\mu{M}$. NAA promoted callus growth at relatively higher concentrations than other auxins tested. IAA was less effective in supporting callus growth. Cytokinin bearing saturated side chain ($N^6$-isopentyladenine) was approximately 30 times more active than the corresponding unsaturated compound, $N^6$-($\D^2$-isopentenyl) adenine. The abilities of cytokinin-autonomous growth were also examined. Callus tissues previously grown on concentrations lower and/or higher than optimal concentrations of cytokinins were better habituated in the subsequent passage. It was suggested that the development of cytokinin autonomy may be related to dosage-concentrations of cytokinin in the previous passage.

• Asian Pacific Journal of Cancer Prevention
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• 제15권24호
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• pp.10543-10555
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• 2015

Breast cancer primary prevention is a high research priority due to the high psychological and economic costs. The disease is a multistep process and several risk factors have been recognized. Over the past three decades numerous studies have investigated the association of lifestyle with breast cancer, showing independent effects of various factors. We report here a summary of the present state of knowledge on the role of lifestyle patterns, such as physical activity, diet, smoking, hormone therapy, and experience of psychological stress in the modulation of breast cancer in women, and discuss commonly accepted biological mechanisms hypothesized as responsible for the associations. The findings indicate that regular physical activity of moderate to vigorous intensity is probably linked with the decreased breast cancer risk among postmenopausal females and suggestive for a decrease of the risk in premenopausal women. In contrast, the consumption of high-fat diet, alcohol intake, and use of combined estrogen and synthetic progestagen hormonal therapy may increase the risk. Epidemiological findings dealing with a role of smoking and experience of psychological stress are conflicting.