• Proceedings of the Korean Society for Environmental Edudation Conference
• /
• 2003.07a
• /
• pp.80-98
• /
• 2003

• Proceedings of the PSK Conference
• /
• 2000.10a
• /
• pp.159.1-159.1
• /
• 2000

• Women's Health Nursing
• /
• v.26 no.3
• /
• pp.250-250
• /
• 2020

• Molecular & Cellular Toxicology
• /
• v.2 no.2
• /
• pp.106-113
• /
• 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.

• Journal of Embryo Transfer
• /
• v.22 no.4
• /
• pp.199-208
• /
• 2007

Although many studies have focused on the biological and toxicological effects of phenol products, in particular, in reproductive tracts, the data about their effects in this estrogenic responsive tissue are much less clear. In addition, the in vitro and in vivo data concerning ED-adverse impacts in other endocrine organs, i.e. pituitary gland, are not understood well either. Thus, a further study is needed for providing a new insight into possible impacts of estrogenic EDs including phenol products in humans and wildlife. A combination of in vitro and in vivo system for examining EDs may bring better understanding into the regulatory mechanisms underlying EDs-induced events. In addition, this information may support for developing optimal screening methods of estrogenic EDs, in particular, phenol products.

• Korean Journal of Environmental Biology
• /
• v.33 no.4
• /
• pp.468-475
• /
• 2015

Nonylphenol is one of endocrine disruptors, as structurally stable, hydrophobic compounds exhibit high condensability and long-lasting in the natural environment. The purpose of this study was to determine the toxic effects of nonylphenol on Daphnia magna. In acute toxicity test, D. magna was exposed for 48 h at concentrations of 0, 10, 18, 32, 56 and $100{\mu}g\;L^{-1}$ nonylphenol. In chronic toxicity test, D. magna were exposed through water for 21 days at concentrations of 0, 1.0, 1.8, 3.2, 5.6 and $10{\mu}g\;L^{-1}$ nonylphenol. Acute toxicity was assessed on the basis of immobility, while chronic toxicity was assessed on the basis of fecundity. The acute toxicity test on nonylphenol was showed that the values of 24 h and 48 h $EC_{50}$ were $25.0{\mu}g\;L^{-1}$ and $13.7{\mu}g\;L^{-1}$, respectively. In chronic test, fecundity was reduced significantly at $5.6{\mu}g\;L^{-1}$ of nonylphenol. These results indicated that nonylphenol have some hazard for acute or chronic toxicity to freshwater invertebrate organism.

• Korean Journal of Environmental Biology
• /
• v.22 no.4
• /
• pp.550-558
• /
• 2004

The effects of postnatal exposure to octylphenol(OP) on the expressions of the steroidogenic enzymes and testosterone production were evaluated. Postnatal male mice (15-day-old) were injected with 2 or 20mg $kg^{-l}$ body weight (BW) of OP for 5 days and sacrificed on postnatal day 21. Testosterone concentration was measured by radioimmunoassay and the expressions of the testicular genes were determined by RT-PCR analyses. Significant reductions in the mean body and testis weight were observed in the OP treated animals. No marked alteration in the histological structure of the testis were observed, however, slight reduction in the seminiferous tubule diameter and the number of Leydig cells and several pyknotic cells could be identified in the 20 mg $kg^{-l}$ BW of the OP treated animals. Serum testosterone concentration was dramatically reduced and the mRNA expressions of the steroidogenic acute regulatory protein (StAR), cholesterol side-chain cleavage enzyme (P450scc) and $17\beta$-hydroxylase/Cl7-20 lyase $(P450_{17\alpha})$ were decreased. No significant changes of the gene expressions of the steroidogenic factor-l (SF-I) and estrogen and androgen receptor after the OP treatment showed that the decreased expressions of the steroidogenic enzymes in the present study did not correlate with these genes. Altogether, the present study demonstrates that postnatal treatment of OP inhibits steroidogenesis by decreasing the transcriptional expressions of the StAR and steroidogenic enzymes. The alteration in steroidogenesis may adversely affect the normal development of the testis and sper- matogenesis.

• Journal of the East Asian Society of Dietary Life
• /
• v.25 no.4
• /
• pp.691-702
• /
• 2015

This study examined the levels of risk perception of food risk elements by adopting a psychometric paradigm and analyzed factors affecting concerns about food risk elements to obtain basic materials for food safety policy. The data were collected from 296 housewives in Daegu, Korea, by a self-administered questionnaire. Frequency distributions, Pearson's correlation coefficient analysis, factor analysis, Cronbach's ${alpha}$, and multiple regression analyses were conducted by SPSS 21.0. The mean level of concern for food safety was 3.75/5.00 points, and the mean percentage of correct answers about heavy metal contamination was highest among food risk elements. The respondents perceived radioactive contaminated foods, GM foods, and endocrine disruptors as a new, delayed, scientifically unknown, involuntary, serious, and uncontrollable risk in risk perception. According to the result of factor analysis for risk perception, two factors such as non-controllability and dread were categorized. In the risk perception map, radioactive contaminated foods and GM foods were considered as an uncontrollable and dreaded risk, heavy metal contamination, endocrine disruptors, and pesticide residues as a controllable and dreaded risk, and foodborne illness and food additives as a controllable and less dreaded risk. On the other hand, the levels of concerns about food risk elements were higher in order of radioactive contaminated foods, GM foods, and endocrine disruptors. The results of multiple regression analysis showed that age, concern for food safety, percentage of correct answers about food risk elements, non-controllability, and dread influenced the concerns about food risk elements. These results imply that food safety policies should consider differences in consumer's risk perception of food risk elements.

• Development and Reproduction
• /
• v.4 no.1
• /
• pp.95-100
• /
• 2000

A large number of man-made chemicals that have been released into the environment have the potential to disrupt the endocrine system of animals and humans. There is a critical developmental period during which sexual brain differentiation proceeds irreversibly under the influence of gonadal hormone. Recently we identified KAP3 gene expressed during the critical period of rat brain sexual differentiation. KAP3 functions as a microtubule-based motor that transports membranous organelles anterogradely in cells, including neurons. In the present study, we aimed to investigate the effect of endocrine disrupter, Dichlorodiphenyl trichloroethane (DDT), on the KAP3 gene expression during critical period of rat brain development. Maternal exposure to DDT increased the level of KAP3 mRNA in male and female fetus brains when examined on the gestational day 17 (GDl7). In postnatal day 6, DDT suppressed the expression of KAP3 gene in male and female rat brain. Also, the body weight and fertilization rate were decreased in the DDT exposured rats. These results showed that endocrine disrupter, DDT, can affect the transcriptional level of brain sexual differentiation related gene, KAP3, in the prenatal and the neonatal rat brain and that maternal exposure to endocrine disruptors may lead to a toxic response in embryonic differentiation of brain. And so KAP3 gene may be used a gene maker to analyse the molecular mechanism for toxic response in animal nerve tissues exposed to endocrine disruptors.

• Development and Reproduction
• /
• v.13 no.4
• /
• pp.217-226
• /
• 2009

Effects of sera from several fish species on monolayer formation, viability and functions of catfish hepatocytes were investigated to establish a primary hepatocyte culture system for screening endocrine disruptors. Hepatocytes of Korean catfish (Silurus asotus) were attached and formed monolayer using the media supplemented with their own serum or sera from eel and tilapia, but not with fetal bovine serum (FBS). The amount of fish sera (0.5~3%) for monolayer culture of the catfish hepatocytes was less than 1/10 of FBS (5~20%) that is commonly used for primary culture of hepatocytes of other species. The results indicate that FBS can be replaced with sera from some fish species and the fish sera are more effective than FBS in maintaining the shape and functions of the hepatocytes. The primary culture of catfish hepatocytes was maintained monolayer with fish sera for at least 10 days, which makes possible to be used for screening the activities of endocrine disruptors. In conclusion, the primary culture system of hepatocytes with fish sera in the present study could be a useful tool for screening and studying endocrine disruptors.