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

• Journal of Life Science
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• v.19 no.9
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• pp.1309-1313
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• 2009

Endocrine disruptors are chemicals which can be found in our normal daily lives. Chemicals such as bisphenol A, DDT, benzophenone and phenylphenol can be easily ingested through plastic food containers and pesticides. Endocrine disruptors can be very harmful and toxic because they disrupt the normal function of the endocrine system. It has been reported that endocrine disruptions can cause fatal strikes in the cardiovascular, reproductive, and central nervous systems, and other parts of the body. Therefore we examined if benzophenone as an endocrine disruptor inhibits development in or induces malformation of chick embryos. Chick embryos which received a single injection of benzophenone ($1{\mu}g$/egg $\sim$ $500{\mu}g$/egg) via the yolk sac at designated times (6, 9, 12, 15, 18 and 21 days after incubation) were investigated. Body weight reduction was observed in middle doses ($40{\mu}g$/egg $\sim$ $60{\mu}g$/egg). High mortality rates and teratogenic signs such as abnormal wry beak and abnormal eyeballs were seen in high doses ($80{\mu}g$/egg $\sim$ $500{\mu}g$/egg). In conclusion, it is suggested that benzophenone induces malformation of chick embryos and seriously inhibits development.

• Toxicological Research
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• v.16 no.2
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• pp.163-172
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• 2000

Recently, there is a worldwide concern that a great number of man-made chemicals have a hormone-like action both in humans and in animals. DECD is developing screening programs using validated test systems to determine whether certain substances may have an effect in humans. In the present study. the establishment oj repeated-dose toxicity test method was tried. Flutamide. an anti-androgenic agent. was administered by gavage to Sprague-Dawley rats for 28 days at dose levels of 0. 0.5. 3 and 18 mg/kg body weight (10-15 rats/sex/group) to examine the effects on general findings. especially reproductive and endocrine parameters. Clinical signs. body weights, food consumption, and sexual cycle were checked and measured. For the gross and microscopic examinations. 10 rats/sex/group were sacrificed at the end of dosing period and the remaining animals of control and high dose groups (5 each) were sacrificed after 14 days recovery. Examinations for hematology and clinical chemistry were carried out at necropsy. There were no treatment-related changes in clinical signs. body weights, food consumption. gross necropsy. hematology and clinical chemistry at all doses of both sexes. The period and regularity of sexual cycle were not adversely affected at all doses by the test agent. At 18 mg/kg. both decreased weights of prostate, seminal vesicle and epididymis in males and increased weights of spleen and thymus in females were observed. In addition, decreased number of spermatids and sperms. increased serum testosterone concentration and increased incidence (100%) of interstitial cell hyperplasia were seen in males. At 18 mg/kg of the recovery group. decreased prostate weight. reduced sperm count and increased incidence (20%) of interstitial cell hyperplasia in males and increased thymus weight in females were observed. At 3 mg/kg. reduced sperm count was found. There were no adverse effects on parameters examined at 0.5 mg/kg of both sexes. The results suggested that the potential target organs of flutamide may be accessory sexual glands including testes for males and spleen and thymus for females. Taken together. this test method was found to be a useful screening test system for endocrine disrupting chemicals.

• Korean Journal of Microbiology
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• v.45 no.1
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• pp.82-85
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• 2009

Endocrine disrupting chemicals (EDCs) disturb animal hormonal system even at very low concentrations, and finally give harmful effects to human through the food web. A white rot fungus Phlebia tremellosa isolated in Korea, was reported to have good degrading activity against the endocrine disrupting phthalates. However, this fungus has very low manganese peroxidase (MnP) activity under various culture conditions while laccase and lignin peroxidase activities were high. We have isolated an MnP cDNA from Trametes versicolor which was involved in the degradation of EDCs, and constructed an MnP expression vector to use in the genetic transformation of P. tremellosa in order to get higher MnP producing strains. Many transformants had integrated expression vector in their chromosomal DNAs, and showed increased MnP activity. One of two transformants showed increased degradation of 4 EDCs (70${\sim}$88%) than the wild type (30${\sim}$45% degradation rates), and showed twice better removal of estrogenic activities generated by the EDCs than the wild type.

• The Journal of Pediatrics of Korean Medicine
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• v.15 no.1
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• pp.105-115
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• 2001

The relation of endocrine in the western medicine and zangfu-organ functions in Korean medicine, related to growth disturbance, was studied and derived the following results. 1. The hormone most related to growth disturbance is, directly secreted from the anterior pituitary or is stimulated and secreted in the target grands, growth hormone, thyroid, adrenocortical hormone, gonadial hormone and is insulin secreted from $\beta$ cell of langerhans' slands of pancreas. 2. the pituitary has the most close relation with the kidney in the five zang-organ. Because the kidney is innate origin(先天之本) and promotes qi and blood(生化氣血), stores the essence of life(藏精), dominates the bones(主骨) and promotes the marrow(生骨髓). Especially it is connected with brain(通於腦). 3. In the children growth, the endocrine action in the pituitary has the most close relation with the kidney, As in the reports of the brain and spinal cord, bone, store essence of life, sexual maturation and decline(kidney-qi, sexual functions of both sexes(天癸)) etc, and cause of cretinism, dwarf in the main subject. 4. Somatomedin is the most important factor of the growth factors, IGF in another word. The unification of IGF and secretion is controlled firstly according to growth hormone, however is very closely related to the nutrition status in the non-hormonic causes. Also, it is affected very much by the insulin. 5. Insulin is one of the important hormone related to the growth and is secreted from the pancreas. Pancreas belongs to the functional system of spleen in oriental medicine, thus the growth disturbance, occurred due to error in insulin secretion and nutrition(in another words, the lack of postnatal essential substance from food-stuff(水穀精氣)), is closely related to the spleen. 6. From the results driven above, the hormone action of endocrine and problem in secretion, related to the growth disturbance, must be focused on the differentiation of symptoms and signs of the kidney and the spleen in oriental medicine.

• The Korean Journal of Physiology and Pharmacology
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• v.15 no.3
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• pp.137-142
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• 2011

Extremely low frequency magnetic fields (ELF-MF) have the ability to produce a variety of behavioral and physiological changes in animals. The stomach, as the most sensitive part of the neuroendocrine organ of the gastrointestinal tract, is crucial for the initiation of a full stress response against all harmful stress. Thus, the purpose of this study was to examine whether ELF-MF stimuli induce changes in the activity of neuroendocrine cells, considering their involvement in endocrine or paracrine effect on surrounding cells. The exposure to ELF-MF (durations of 24 h and 1 or 2 weeks, 60 Hz frequency, 0.1 mT intensity) altered the distribution and occurrence of gastrin, ghrelin and somatostatinpositive endocrine cells in the stomach of rats. The change, however, in the secretion of those hormones into blood from endocrine cells did not appear significantly with ELF-MF exposure. Comparing with sham control, ELF-MF exposure for 1 and 2 week induced an increase in $BaSO_4$ suspension propelling ratio of gastrointestinal tract, indicating that ELF-MF affects gastrointestinal motility. Our study revealed that ELF-MF exposure might influence the activity of endocrine cells, an important element of the intrinsic regulatory system in the digestive tract. The pathophysiological character of these changes and the mechanism responsible for neuroendocrine cell are still unclear and require further studies.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.4
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• pp.276-284
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• 2022

Endocrine-disrupting chemicals found in many commercial products may interfere with the normal functioning of the endocrine system and are unsafe because of their cumulative effect on the human body. However, little is known about the effects of combinations of endocrine-disrupting chemicals in humans. Methoxychlor and bisphenol A are toxic to male reproductive organs. Therefore, we studied the effects of methoxychlor and bisphenol A on male reproductive function. Male mice were divided into four treatment groups: control, 400 mg methoxychlor, 1 mg bisphenol A, and 400 mg methoxychlor + 1 mg bisphenol A/kg/day. Methoxychlor and bisphenol A were dissolved in sesame oil and acetone and administered orally for 4 weeks. After administration, the weight and histological changes in the testicles and epididymis, sperm count and health were observed biochemical tests and whole blood counts were performed. The results showed that the mice in the bisphenol A and methoxychlor + bisphenol A groups gained more weight than those in the control and methoxychlor group. The weights of the testes and epididymis were higher in the experimental groups than in the control. Sperm motility and progression were significantly reduced in the bisphenol A and methoxychlor + bisphenol A groups. Histological observation showed a reduced number of sperm, smaller seminiferous tubules, and destroyed lumen in the methoxychlor + bisphenol A group compared to the other groups. In conclusion, our study showed that methoxychlor and bisphenol A destroy male reproductive tissues and decrease sperm quality.

• Journal of Korean Society of Water and Wastewater
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• v.20 no.6
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• pp.893-904
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• 2006

To improve sensitivity of biosensor as yeast two-hybrid detection system for estrogenic activity of suspected chemicals, we tested effects of several combinations of the bait and fish components in the two-hybrid system on Saccharomyces cerevisiae inducted a chromosome-integrated lacZ reporter gene that was under the control of CYC1 promoter and the upstream Gal4p-binding element $UAS_{GAL}$. The bait components that were fused with the Gal4p DNA binding domain are full-length human estrogen receptor ${\alpha}$ and its ligand-binding domain. The fish components that were fused with the Gal4p transcriptional activation domain were nuclear receptor-binding domains of co-activators SRC1 and TIF2. We found that the combination of the full-length human estrogen receptor ${\alpha}$ with the nuclear receptor-binding domain of co-activator SRC1 was most effective for the estrogen-dependent induction of reporter activity among the two-hybrid systems so far reported. The relative strength of transcriptional activation by representative natural and xenobiotic chemicals was well correlated with their estrogenic potency that had been reported with other assay systems.

• Toxicological Research
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• v.16 no.1
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• pp.33-37
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• 2000

Hershberger assay is known as one of the in vivo-short-term scrrning assays for endocrine disrupting chemicals (EDCs), but this method is not a validated test system. In the present study, the establishment of Hershberger assay to detect EDCs was tried using a model substance, di(n-butyl)phthalate (DBP), a plasticizer for plastics. Thirty-six immature male rats were randomly assigned to six groups: DBP 0, 40, 200, and 1000mg/kg, a positive control (flutamide 20 mg/kg), and a combination group(DBP 1000mg/kg and testosterone 50 ug/kg). DBP and flutamide were administered by gavage to male rats from day 21 to 40 post partum. Testosterone was subcutaneously injected during the same period. We evaluated body weigth gain, weights of ventral prostate, seminal vesicle, and levator ani and bulvocavernous muscle, and serum concentrations of testosterone and lutenizing hormone in male rats. The weights of seminal vesicle and levator ani and bulvocavernous muscle of males receiving 1000mg/kg of DBP was significantly lower than controls. There was no effect of DBP-treatment on body weight gain, prostate weight, and hormone concentrations. In the positive control group, the weights of seminal vesicle and levator ani and bulvocavernous muscle of males receiving 20mg/kg of flutamide were significantly lower than controls. In the combination group, there was no effect of co-treatment of DBP and testosterone on all parameters effect against DBP. This method was found to be a useful short-term screening assay system for EDCs.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.2
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• pp.86-92
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• 2007

In this study, we tried to quantitatively study the distribution of estrogenic activity in sediment from Gwangyang Bay by E-screen assay. Besides, we compared the estrogenic activity and the concentration of chemical pollutants. The highest estrogenic activity was recorded at the stations(GY6 and GY8) close to industrial complex and the river mouth of Seomjin. These results obtained from the E-screen assay similar to those of simultaneous analytical detection of 310 chemicals. In particular, GY6 and GY8 sites are confirmed as the full agonist sites because of their RPE values were over 90% having strong estrogenic effect. Also, their EEQ(Estradiol Equivalency Quantity) values are 35.6 ng/g and 14.6 ng/g, low than that of other sites, and these results suggests that have relatively high estrogenic efficiency in Gwangyang Bay. From these results, we can estimate that the stations close to industrial complex and the river mouth of Seomjin are major sources of endocrine disrupter in Gwangyang Bay. On the other hand, when we tried to compare the endocrine disrupter activity and $COD_{Mn}$ value, that is not correlated.