• Development and Reproduction
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• v.17 no.1
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• pp.55-62
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• 2013

Puberty is the developmental period which animals obtain the ability of reproducing sexually for the first time in life. In commercially important aquaculture fish species, the onset of puberty is a matter of major interest due to controlling of sexual maturation to improve broodstock management. To investigate pubertal characteristics of female longtooth grouper (Epinephelus bruneus), specimens were classified into three groups by the bodyweight, including 1, 2, and 3 kg group. Thereafter, we focused on ovarian development and level changes of endocrine regulation factors (GnRH, GTHs, steroid hormone). In the non-breeding season (April), the levels of endocrine regulation factors showed increasing trends in accordance with bodyweight gaining; nevertheless, the oocytes were growth phase belongs to almost peri-nucleous stages in all groups. In the breeding season (June), the levels of endocrine regulation factors were fluctuated that decreases in levels of sbGnRH and $FSH{\beta}$ mRNA expressions along with serum $E_2$ concentrations in 3 kg of group. However, $LH{\beta}$ mRNA expression levels sustained increasing trends by the bodyweight. Moreover, the oocytes developed that 2 kg and 3 kg groups obtained plentiful vitellogenic oocytes while 1 kg group was still composed with greater part of pre-vitellogenic oocytes. Especially, the oocytes of 3 kg group reached over 450 ${\mu}m$ of diameters that indicating possibility to enter the final maturations. These results suggest that the progress of pubertal development in female E. bruneus could be classify into three phases via bodyweight, including pre-puberty (1 kg), early-puberty (2 kg) and puberty (3 kg).

• Environmental Analysis Health and Toxicology
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• v.23 no.2
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• pp.93-100
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• 2008

The ecotoxicological effects of 4-tert-octylphenol were observed on Harpacticoid copepoda Tigriopus japonicus s.l. gathered and cultured from tidal pool of Korean coast. There were no significant differences in survival rate (except 10 $\mu$g/L; 70.00%) and sex ratio (except 30 $\mu$g/L) on T. japonicus s.l. exposed to 4-tert-octylphenol. However, 4-tert-octylphenol induced developmental delay (copepodite emergence day and adult male mergence day) and retardation of first brooding day of adult female. Moreover the body size and biomass decreased at 4-tert-octylphenol exposure. As a result, detailed life-cycle research of T. japonicus s.l. may yield potential bioindicators for environmental monitoring and assessment.

• Toxicological Research
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• v.18 no.4
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• pp.401-409
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• 2002

Phthalate esters have possible effects on the endocrine system. Di-n-butyl phthalate (DBP) is one of the most commonly wed phthalic acid esters (PAEs). It is extensively wed as a plasticizer in elastomers, as a solvent for printing inks and resins, and as a textile lubricating agent. It is also present in the formulations of various cosmetic products. DBP has been identified as a reproductive toxicant in several animal species and also know as a endocrine disruptor. The objective of this study was to investigate the effect of DBP on developmental immune Junction wing rat pups as experimental animals. Timed-bred pregnant SD rats were orally dosed with 0, 250, 500, or 750 mg DBP/kg body weight once a day from gestational day (GD) 5 to 18 and postpartum day (PD) 3 to 18. On PD22, the dams and their pups were euthanized and examined for alteration in parameters associated to immune function. The results showed no significant changes in body weight, thymus weight, thymus and spleen cellularities, the polyclonal activation respones of splenocyte with ConA and LPS, and also the distribution of arterial blood cells and thymocyto subsets in both rat dam and pups. However DBP exposure on rat dam resulted in increases of liver weights of dam and their pups except 750 mg DBP/kg, and body and spleen weights in pups except 750 mg DBP/kg. On the other hands, distribution rates of CD8+ T cells at 500 mg DBP/kg and B cells at 750 mg DBP/kg among splenocyte subsets were significantly increased in rat pups, unlike dams. Reasons of these distribution alterations of CD8+ T cells and B cells in rat pups are under study.

• Development and Reproduction
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• v.27 no.4
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• pp.185-193
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• 2023

Although increasing evidence of cause-and-effect relationship between BPA exposure and female reproductive disorders have been suggested through many studies, the precise biochemical and molecular mechanism(s) by which BPA interferes with steroidogenesis in the ovarian cells still remain unclear. Therefore, the purpose of this study was to discover the steroidogenic biomarker(s) associated with BPA treatment in human granulosa cell line, KGN. In this study, our results obtained via the analysis of steroidogenesis-related protein expression in KGN cells using quantitative polymerase chain reaction (qPCR) and western blot analyses revealed that the expression levels of steroidogenic acute regulatory (StAR) and aromatase decreased considerably and gradually after BPA treatment in a dose-dependent manner under BPA treatment. Further, remarkable decreases in their expression levels at the cellular levels were also confirmed via immunocytochemistry, and subsequent StAR and aromatase mRNA expression levels showed profiles similar to those observed for their proteins, i.e., both StAR and aromatase mRNA expression levels were significantly decreased under BPA treatment at concentrations ≥0.1 μM. We observed that follicle stimulating hormone upregulated StAR and aromatase protein expression levels; however, this effect was suppressed in the presence of BPA. Regarding the steroidogenic effects of BPA on KGN cells, controversies remain regarding the ultimate outcomes. Nevertheless, we believe that the results here presented imply that KGN cells have a good cellular and steroidogenic machinery for evaluating endocrine disruption. Therefore, StAR and aromatase could be stable and sensitive biomarkers in KGN cells for the cellular screening of the potential risk posed by exogenous and environmental chemicals to female reproductive (endocrine) function.

• Clinical and Experimental Pediatrics
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• v.55 no.7
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• pp.224-231
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• 2012

Prader-Willi syndrome (PWS) is a complex multisystem genetic disorder characterized by hypothalamic-pituitary dysfunction. The main clinical features include neonatal hypotonia, distinctive facial features, overall developmental delay, and poor growth in infancy, followed by overeating with severe obesity, short stature, and hypogonadism later in development. This paper reviews recent updates regarding the genetic aspects of this disorder. Three mechanisms (paternal deletion, maternal disomy, and deficient imprinting) are recognized. Maternal disomy can arise because of 4 possible mechanisms: trisomy rescue (TR), gamete complementation (GC), monosomy rescue (MR), and postfertilization mitotic nondisjunction (Mit). Recently, TR/GC caused by nondisjunction at maternal meiosis 1 has been identified increasingly, as a result of advanced maternal childbearing age in Korea. We verified that the d3 allele increases the responsiveness of the growth hormone (GH) receptor to endogenous GH. This paper also provides an overview of endocrine dysfunctions in children with PWS, including GH deficiency, obesity, sexual development, hypothyroidism, and adrenal insufficiency, as well as the effects of GH treatment. GH treatment coupled with a strictly controlled diet during early childhood may help to reduce obesity, improve neurodevelopment, and increase muscle mass. A more active approach to correct these hormone deficiencies would benefit patients with PWS.

• Environmental Analysis Health and Toxicology
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• v.14 no.1_2
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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.

• Proceedings of the Korean Society of Toxicology Conference
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• 2003.05a
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• pp.102-102
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• 2003

Diethylhexyl phthalate (DEHP) was known as endocrine disrupter revealing reproductive / developmental toxicity. For a long time, risk due to DEHP released from PVC medical devices was became an issue for patient receiving blood bag, iv injection solution like saline and Hartman's solution. This study was conducted to suggest permissible intake level (PIL) of DEHP based on reproductive toxicity, to quantify daily intake level of DEHP can be exposed to patient through various medical treatment and to estimate risk values of DEHP released from PVC medical devices.(omitted)

• Asian-Australasian Journal of Animal Sciences
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• v.23 no.12
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• pp.1668-1676
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• 2010

The somatotropic axis plays a key role in proliferation and differentiation of avian organs during both pre- and posthatching periods. This review discusses the complexity of regulation of the endocrine system for chicken development and growth by growth hormone (GH), insulin-like growth factor (IGF), and IGF binding protein (IGFBP). In addition, the thyrotropic axis, including thyrotropin-releasing hormone (TRH) and thyroid hormones ($T_4$ and $T_3$), is also involved in the GH-secreting pattern. In mammals, IGFI and -II are always sequestered in a 150 kDa non-covalent ternary complex. This complex consists of one molecule each of IGF-I or IGF-II, IGFBP-3 or IGFBP-5 and an acid labile subunit (ALS). Chick ALS is identified in different strains for the first time, and further investigation of the expression of ALS on developmental stage and ALS effect on IGF bioavailability may be addressed in the future.

• Development and Reproduction
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• v.18 no.4
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• pp.187-195
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• 2014

Polycyclic aromatic hydrocarbons (PAHs), which are ubiquitous in the air, are present as volatile and particulate pollutants that result from incomplete combustion. Most PAHs have toxic, mutagenic, and/or carcinogenic properties. Among PAHs, benzo[a]pyrene (B[a]P) and dimethylbenz[a]anthracene (DMBA) are suspected endocrine disruptors. The testis is an important target for PAHs, yet effects on steroidogenesis in Leydig cells are yet to be ascertained. Particularly, disruption of testosterone production by these chemicals can result in serious defects in male reproduction. Exposure to B[a]P reduced serum and intratesticular fluid testosterone levels in rats. Of note, the testosterone level reductions were accompanied by decreased steroidogenic acute regulatory protein (StAR) and $3{\beta}$-hydroxysteroid dehydrogenase isomerase ($3{\beta}$-HSD) expression in Leydig cells. B[a]P exposure can decrease epididymal sperm quality, possibly by disturbing the testosterone level. StAR may be a key steroidogenic protein that is targeted by B[a]P or other PAHs.

• Journal of Environmental Health Sciences
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• v.31 no.4 s.85
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• pp.254-259
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• 2005

Permethrin, a synthetic pyrethroid insecticide, has been widely used to protect domestic animals and the public health, as well as in agriculture against a variety of pests, which provides potential for environmental exposure. Permethrin is classified as possible human carcinogen and endocrine disrupting chemical by many international authorities. However, its developmental effects have been rarely studied. This study investigated the effects of permethrin during embryo-genesis. Developmental toxicity of permethrin was evaluated using short-term in vitro battery system. Gestation day 9.5 rat embryos (organogenesis) were cultured with permethrin (0.1,0.4 and 0.8 mg/ml) for 48 hours using whole embryo culture system. All the treatments exhibited significant decreases in the total morphological score. Permethrin induced significant growth retardation and the developmental abnormality at doses of 0.4 and 0.8 mg/ml. Moreover, the DNA and protein contents of embryos decreased in dose-dependent manner. These observations suggest that permethrin contributes to toxicity on embryonic developments in rats.