• 한국환경보건학회:학술대회논문집
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• 한국환경보건학회 2004년도 International Conference Current Challenges and Advances in Environmental Health
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• pp.81-82
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• 2004

• Toxicological Research
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• 제18권1호
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• pp.59-64
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• 2002

Substantial evidences have been accumulated about the hormone-like effects of exogenous substances such as pesticides and industrial chemicals during past years. The effects of these substances on the endocrine system are believed to be either enhancing or reducing of various endocrine action. It is necessary to identify putative causal agents by the batter system and to assess their ability to disrupt the endocrine system. A variety of in vitro and In vivo approaches have been used to determine the androgenic effects of environmental chemicals. To establish the method for assessment of the putative endocrine disruptors with androgenic activity, we carried out the cell proliferation assay by MTS method after treatment with the various concentration of testosterone in LNCaP cells (human prostatic cancer cell line) and also observed the expression of androgen-related genes by quantitative RT-PCR. In the cell proliferation assay, the results showed that the grouth of LNCaP cells increased within level of at least 10pM testosterone. We measured by quantitative RT-PCR method on the effects of testosterone on mRNA expression of androgen receptor (AR), prostate-specific antigen (PSA), bone morphogenetic protein (BMP) and BMP receptor (BMPR) In LNCaP cells. The results demonstrated that mRNA expression of PSA and BMPR-IB was observed differently within level of at least 0.01 pM testosterone compared with non-treated control. These observations suggest that the detection of PSA and BMPR-IB mRNA by the quantitative RT-PCR in LNCaP cells is very sensitive method to identify the endocrine disruptors to have the androgenic effects.

• Animal cells and systems
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• 제3권2호
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• pp.193-197
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• 1999

A peroxidase-antiperoxidase method was used to detect the cells showing immunoreactivities to six hormone antibodies in the alimentary tracts of six frog species, Rana nigromaculata, R. rugosa, R. amurensis coreana, R. catesbeiana, Bombina orientalis, and Hyla arborea japonica, inhabiting Korea. The cells immunoreactive to gastrin and cholecystokinin-8 were observed in the pylorus of the stomachs and in the small intestines of all frog species examined. In contrast, these somatostatin-immunoreactive cells were identified in the esophagus and the whole gastrointestinal tracts, but were absent from the large intestines in R. rugosa, R. catesbeiana, B. orientalis and H. arborea japonica. The pancreatic polypeptide (PP)-immunoreactive cells represented their distribution limited to the small intestines of R. amurensis coreana and H. arborea japonica, and they were additionally identified in the pylorus of the stomachs in the other four species. Serotonin- and glucagon- Immunoreactive cells revealed different regional distributions in which the former were observed throughout the whole alimentary tracts in all frog species investigated, whereas the latter were not found in these regions at all. Endocrine cells were relatively abundant in the pyloric portion of the stomach compared to other organs. The present study showed that all endocrine cells except for PP had a similar distribution in the alimentary tracts of all frog species used.

• 대한의생명과학회지
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• 제10권4호
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• pp.403-406
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• 2004

Environmental endocrine disruptors (EDs) are toxic, hormone-like chemicals which can be found in our normal daily life. We have examined if EDs can inhibit the monocellular microorganisms such as lactic acid bacteria or if the growth of lactic acid bacteria could be resistant to the endocrine disruptors. We have used Lactobacillus paracasei subsp. paracasei (KCTC No. 3165) as an experimental strain and bisphenol A, benzophenone and phenylphenol for the comparison purpose. Experiments included the evaluation of turbidity, absorbance and actual cell counts. We found that No.3165 was somewhat resistant to EDs naturally, however, high concentration of EDs could inhibit the growth of No. 3165 completely. Different EDs showed different spectrum of inhibit. This study should contribute to the development of more resistant lactic acid bacteria to EDs and to the development of functional fermented beverage.

• 한국응용곤충학회지
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• 제34권1호
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• pp.20-32
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• 1995

Adult diapause in insects is characterized by suppression of reproductive development. It is induced by environmental cues such as photoperiod, temperature, food availability, and other conditions Diapause-inducing environment is recognized and analyzed by the brain of the insects. The interpreted information is conveyed via endocrine system to target tissues such as ovaries, fat body, and other tissues. From this signal hierarchy of a brain-endocrine-target tissue axis, several factors are involved to express a diapause trait in a quantitative mode, even though the insects show a binomial phenotye between being in diapause or not. Recent works estimated that the number of the factors is relatively small by a series of crossing trials between high and low diapause lines. Heritability of the diapause is quite high (ca. 70%) in some species. Epistasis, sex-linkage, pleiotropism, and other nongenetic components also affect diapause inheritance. Most physiological studies have been focused on control mechanisms of the juvenile hormone (JH) synthesis in corpora allata (CA) because JH level in hemolymph of teneral adults is critical to decide a later developmental mode. Allatostatin, an antagonizer of JH synthesis, has been believed to be a potent brain message to CA for adult diapause induction.

• 대한임상검사과학회지
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• 제49권4호
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• pp.495-497
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• 2017

Thalassemia major is a genetic disorder with a defective synthesis of either the alpha or the beta chain of hemoglobin A. Blood transfusion is crucial for the survival in these patients. Unfortunately, endocrine dysfunction is a very common complication in these patients and is principally due to excessive iron overload as a result of frequent blood transfusions. Although regular blood transfusion may increase life expectancy, disturbances in growth and pubertal development, abnormal gonadal functions, impaired thyroid, parathyroid and adrenal functions, diabetes, and disorderly bone growth are common side effects. We hereby present a case of a 23-year-old, unmarried woman with beta thalassemia major presenting with primary amenorrhea, poor development of secondary sexual character, and short stature. Thorough history, clinical examination, and laboratory investigation, including dynamic function test (insulin tolerance test) were conducted. These tests confirmed that she had multiple endocrinopathies, including hypogonadotropic hypogonadism, growth hormone deficiency, and subclinical adrenal insufficiency, which were caused by iron overload. She required hormone replacement therapy. Early recognition of possible deficiencies in hypothalamo-pituitary-end organ hormones caused by iron overload in thalassemia patients that undergo frequent blood transfusion procedures is essential. Appropriate treatments, including transfusion regimen and chelation therapy, as well as specific treatment of each complication are the crucial for the successful management and improvement of quality of life these patients.

• Molecules and Cells
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• 제27권5호
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• pp.547-556
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• 2009

Parathyroid hormone is the most important endocrine regulator of calcium concentration. Its N-terminal fragment (1-34) has sufficient activity for biological function. Recently, site-directed mutagenesis studies demonstrated that substitutions at several positions within shorter analogues (1-14) can enhance the bioactivity to greater than that of PTH (1-34). However, designing the optimal sequence combination is not simple due to complex combinatorial problems. In this study, support vector machines were introduced to predict the biological activity of modified PTH (1-14) analogues using mono-substituted experimental data and to analyze the key physicochemical properties at each position that correlated with bioactivity. This systematic approach can reduce the time and effort needed to obtain desirable molecules by bench experiments and provide useful information in the design of simpler activating molecules.

• Clinical and Experimental Reproductive Medicine
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• 제18권2호
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• pp.189-196
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• 1991

Long-term administration of luteinizing hormone-releasing hormone(LHRH) agonists, through a process of pituitary desensitization and down-regulation of receptors, inhibits the secretion of gonadotropin and sex-steroids and induces a reversible suppression of gonadal activity. This approach can be used as an effective endocrine therapy for some hormone-dependent tumors. We have used D-Trp6-LHRH, a long acting LHRH agonist, for the treatment of eleven patients with uterine leiomyomas, thereafter myomectomy was performed in seven cases and observed the ultrastructural changes of leiomyoma with an electron microscope. The use of LHRH agonist may be effective in reducing the size of a myoma considerably by primarily inducing medical hypophysectomy and would allow easier surgical removal. Electron microscopic findings of myoma cells after the use of LHRH agonist included the following: loss of cristae and swelling nuclear chromatin, perinuclear vacuolation in cytoplasm. Bone mineral density was slightly decreased, however, the difference was not statistically significant.

• 환경생물
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• 제20권3호
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• pp.224-231
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• 2002

광주기(하루 중 빛의 길이)는 골든 햄스터의 생식을 조절하는 주된 요인이다. 광주기 정보는 멜라토닌을 통하여 생식 내분비계로 전달된다. 따라서 멜라토닌이 생식에 미치는 효과를 여러 광주기에 노출시킨 햄스터에서 조사하였다. 단주기(하루 중 12시간 이하의 조명)에 노출시킨 동물들과 저녁에 멜라토닌을 주사한 동물들의 정소 무게는 현저하게 줄어들었으나, 장주기 (하루 중 12.5시간 이상의 조명)에 유지된 동물과 오전에 멜라토닌을 투여한 동물들의 정소 무게는 줄어들지 않았다. 퇴화된 정소를 조직학적으로 조사한 결과, 세정관 직경이 감소되었고, 세정관내 세포수가 두드러지게 줄어들었다. 또한 생식 능력이 퇴화된 동물의 혈중 여포자극호르몬과 황체호르몬의 수준도 생식 능력을 보유하고 있는 동물에 비해 뚜렷하게 감소하였다. 멜라토닌 수용체가 역전사 polymerase chain reaction으로 동정되었고 조직특이성 또한 조사하였다. 동정된 멜라토닌 수용체는 309염기였으며, 시상하부와 뇌하수체를 포함하는 다양한 장기에서 발현되었다. 생식을 조절하는 핵심 물질인 gonadotropin releasing hormone (GnRH) 유전자의 발현 또한 동정되었다. 그러나 멜라토닌 처리와 광주기 처리는 GnRH유전자 발현에 영향을 미치지 않았다. 종합하면, 광주기의 효과는 멜리토닌을 경유하여 발휘되며, 멜라토닌은 GnRH유전자의 발현보다는, 생성된 GnRH의 분비에 영향을 미쳐 생식내분비계에 간접적으로 작용함을 알 수 있었다.

• Toxicological Research
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• 제16권1호
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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.