• The Korean Journal of Nuclear Medicine
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• v.15 no.2
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• pp.53-57
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• 1981

The estrogen and progesterone receptors which are bound to the cytoplasmic protein of cancer cells were measured in 20 patients with the early breast cancer by means of radioimmunoassay using charcoal. 1. The Patients with estrogen receptor positive were 13 (65%) of 20 cases and with progestrone receptor positive were 7 cases (35%) in the early breast cancer. 2. Coexistence of estrogen and progesterone receptor positive was noted in 7 cases (35%). The cases of estrogen receptor positive and progesterone receptor negative were 6 cases (33.3%), while there were no cases of estrogen receptor negative with progestrone receptor positive. 3. Coincidence of estrogen and progesterone negative was notied in 7 cases(35%). Conclusively, it is considered that the measurement of estrogen and progesterone receptors has relevance as predictive value, in the response to hormonal manipulations and chemotherapy for breast cancer patients.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.70-70
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• 2003

Estrogen receptor is a ligand-activated transcription factor. Its action depends on the receptor, its ligand, and its coactivator proteins. As a consequence, the concentration of the receptor is a major component that governs the magnitude of the estrogen response. Despite the extensive knowledge on mechanism of estrogen receptor action, regulation of estrogen receptor itself is not very well understood. Estrogen receptor is known to be downregulated under hypoxia leading to inhibition of estrogen receptor mediated transcription activation. We have studied mechanism of loss of estrogen responsiveness under hypoxia. We found that Hif-l${\alpha}$, a major transcription factor regulating hypoxic response, inhibited transcription of estrogen response element driven luciferase gene by expression of HIF-l${\alpha}$/vp16 construct designed to contain transcription activity under normoxia. This loss of estrogen responsiveness appears to be the result of ER${\alpha}$ downregulation. ER${\alpha}$was downregulated at the levels of ligand-biding and protein within l2-24h, and the response was blocked by the proteasome inhibitor MG132, protein synthesis inhibitor cyclohexamide, and tyrosine kinase inhibitor Genistein. These results demonstrate that Hif-l${\alpha}$ downregulates ER${\alpha}$ by proteasome dependent pathway.

• Journal of Nutrition and Health
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• v.28 no.4
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• pp.298-308
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• 1995

To investigate the effect of estrogen and dietary protein level on Ca metabolism, female rats were undergone ovariectomy or sham-operation. Ovariectomized rate were divided into either estrogen-or vehicle-treated groups. Each treatment group was again divided into 40%-casein(H) or 10%-casein(L) diet groups. All experimental diets contained 0.2% Ca, 0.4% P and fed to rats for 8 weeks. Apparant Ca absorption and Ca balance were not affected by dietary protein level and ovariectomy, however they were increased by estrogen injection and this effect was even higher in low protein groups. Urinary Ca excretion were higher in high protein groups. GFR was not affected by dietary protein level, ovariectomy, or by estrogen injection. Urinary protein excretion was higher in high protein groups, which implies that the kidney funtion was deteriorated by high protein diet, and this may account partly for the higher urinary Ca in high protein groups. Ovariectomy or estrogen treatment had no effect on urinary protein excretion. Urinary hydroxyproline was higher in ovariectomized rats and increased in high protein grous. Elevated value of ovarictomized rats was lowered by estrogen injection, especially in low protein group. Alkaline phosphatase tended to increase in ovariectomized groups and lowered with estrogen treatment, but this difference was not statistically significant. Serum PTH was not affected by ovariectomy and dietary protein level. Therefore the increased hydroxproline excretion does not seem to be attributed to PTH. Dietary protein level, ovariectomy and estrogen treatment did not affect the weights and components of femur, scapular, and 4th vertebra. Ash/wt ratio of femur was, however, lower in ovariectomized rats and increased with estrogen treatment. Therefore, among the bones studied, femur seemed to be the most vulnerable. The results of this study shows that estrogen treatment may alleviate or reduce bone loss in postmenopausal women somewhat, especially for those people with low protein diet.

• Journal of the Korean Society of Food Science and Nutrition
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• v.25 no.6
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• pp.993-1005
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• 1996

This study was implemented in order to investigate the effects of dietary calcium-salt, estrogentreatment, and estrogen/calcium treatment on bone metabolism. Ovariectomized rats were used as animal models. Female Sprague-Dawley rats with a body weight of 250~280g were underwent ovariectomy or sham-operation. The ovariectomized rats were divided into 9 different experimental groups including the saline-treated group, the estrogen-treated group, the high calcium salt-treated group, and the estrogen/calcium treated groups and fed for 6 weeks. Creatinine and hydroxyproline in urine were analyzed. Creatinine, calcitonin, osteocalcin, alkaline phosphatase and parathyroid hormone in plasma were also determined. The results of the experiment are as follows : The ovariectomy caused a significant increase in the level of food intake, food effciency ratio and body weight gain in comparison with sham-operation. The overall food intake, food effciency ratio and body weight gain were significantly decreased by estrogen. The ovariectomized animals developed obesity as a result of increased food intake. In addition, estradiol injections suppressed food intake with a concomitant loss in body weight. The level or urinary hydroxyproline, as an indicator or bone resorntion, was higher in the ovariectomized rats compared to sham-opertion, while these decresed in the estrogen/calcium treated group. Parathyroid hormone and calcitonin in the plasma, that were used as the indicator of calcium homeostasis, parathyroid hormone higher in the ovariectomized rats compared to sham-operation. It was lowered by estrogen and high calcium treated groups; thus, estrogen and estrogen/calcium treated groups were decreased by 32% compared to saline treated group. Osteocalcin and alkaline phosphatase which are indicators of bone formation, were significantly higher in ovariectomized group, while this showed to be decreased in the estrogen and the ostrogenicalcium treated groups. Estrogen and estrogen/calcium in ovariectomized rats resulted in lower bone loss. However, estrogen treated group its gradual reduction showed little effect on bone loss, while the gradual reduction of estrogen had a preventive effect on bone loss when the treatment was combined with calcium intensification.

• Proceedings of the PSK Conference
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• 2003.10b
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• pp.109.2-110
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• 2003

Estrogen is the most important endocrine hormone that has reproduction and physiological process in a number of tissues. However, an excess of estrogen can promotes the growth of hormone-dependent breast cancer. Thus the regulation of estrogen level is important a prevention of estrogen-related cancer. It has been reported that some of flavonoids could inhibit estrogen-dependent cancer. And these compounds are expected as chemopreventive agents on estrogen related disease. (omitted)

• Korean Journal of Biological Psychiatry
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• v.8 no.1
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• pp.147-152
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• 2001

Objective : It has been thought that estrogen has neuroleptic like effect in women schizophrenic patients. This study aimed to investigate neuroleptic side-effects severity in women with schizophrenia and to investigate their putative association with variations in sex steroids over menstrual cycle. Based on the estrogen theory, The author hypothesized that parkinsonian side-effects would be exacerbated when estrogen levels were high. Method : 26 schizophrenic women were assessed using the ESRS(Extrapyramidal Symptom Rating Scale) and estrogen analysis. Tests were conducted twice, in the mid luteal and mid follicular phase. Result : It was hypothesized that high level of estrogen would lead to an exacerbation of parkinsonian side-effects but the results indicated that parkinsonian side effects decreased overall when estrogen levels were high. This effects were more marked for the group taking typical neuroleptics than those taking atypical neuroleptics. Conclusion : The results of this study suggest that estrogen and progesteron may reduce the severity of neuroleptic induced extrapyramidal side effects over menstrual cycle in women with schizophrenia. It was concluded that estrogen has different effects on dopamine dynamics in the mesolimbic and mesostriatal pathways according to estrogen, progesteron, catecol estrogen, prolactine.

• Korean Journal of Biological Psychiatry
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• v.5 no.1
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• pp.122-128
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• 1998

Objective : This study was a open clinical trial aimed at exploring the effectiveness of combined treatment with estrogen and antipsychotics to the chronic female schizophrenics. Method : 40 female patients who met DSM-VI criteria for schizophrenia who were chronically ill were randomly assigned to estrogen group(EG) and control group(CG). EG patients were received estrogen 1.25mg for 8weeks in addition to their routine antipsychotic regimens. CG patients were received their routine antipsychotic regimens only. Both groups were evaluated by PANSS(Postive and Negative Syndrome Scale), CGI(Clinical Global Impression) at 0, 4, 8 week during the trial period and compaired with each other. Results : 40 female patients have completed the study during 8weeks. EG was significantly improved in PANSS and CGI scores than CG during the 8weeks. In EG patients, all symptom subtypes(positive symptoms, negative symptoms, general psychopathology symptoms) of PANSS were significantly improved and positive symptoms were most significantly improved at 8week. Conclusions : This results support the clinical value of combined estrogen therapy among chronic female schizophrenics.

• Archives of Pharmacal Research
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• v.20 no.6
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• pp.572-578
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• 1997

To gain further insight into how antiestrogens modulate cell function, the effects of antiestrogen on cell proliferation were studied in human breast cancer cells. We examined the effects of trans-tamoxifen on the proliferation of three human breast cancer cell lines that differed in their estrogen receptor contents. Trans-tamoxifen $(1{\mu}M)$ markedly inhibited the estrogen stimulated proliferation of MCF-7 human breast cancer cells that contained high levels of estrogen receptor $(1.15{\pm}0.03 pmole/mg protein)$ over that of control. In T47D cells that contained low levels of estrogen receptor $(0.23{\pm}0.05 pmole/mg protein)$, trans-tamoxifen $(1{\mu}M)$ showed minimal inhibition of estrogen stimulated cell proliferation over that of control. MDA-MB-231 cells, that contained no detectable levels of estrogen receptors, had their growth unaffected by trans-tamoxifen treatment. These results showed their sensitivity to growth inhibition by antiestrogen conrrelated well with their estrogen receptor content. Also we examined the effect of antiestrogen on cellular progestrone receptor level as well as plasminogen activator activity in MCF-7 cells. Trans-tamoxifen $(1{\mu}M)$ showed maximal inhibition of estrogen stimulated progestrone receptor level as well as plasminogen activator activity in MCF-7 cells that were stimulated by estrogen. It is not clear whether these inhibitions of progestrone receptor and plasminogen activator activity by estrogen are related to the antiestrogen inhibition of cell proliferation of MCF-7 cells. From the results of this study, it is clearly demonstrated that trans-tamoxifen is an antiestrogen in MCF-7 human breast cancer cells. Our data suggest that the biological effectiveness of trans-tamoxifen appear to result from its affinity of interaction with the estrogen receptor.

• The Korean Journal of Pharmacology
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• v.6 no.1
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• pp.45-55
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• 1970

It is well known that the uterine contractility is affected by sexual hormone. In this experiment, the authors attempted to study the influences of testosterone and estrogen or the uterine contractility to oxytocics. The contractile sensitivity of the excised uterine muscle of non-castrated and castrated rabbits with testosterone and estrogen 24 hours before experiment is observed respectively. And the cholinesterase activity and electrolytes (Na, K, Ca and Mg) in the uterine muscle are measured in order to study the relationship with contractile sensitivity and those changes. The results obtained were summarized as follows: 1. The contractile effect of spareng on the excised uterine muscle of non-castrated rabbits pretreated with estrogen was markedly increased in small dose, but that of rabbits pretreated with testosterone was significantly increased in large dose, comparing with that of the control group. In castrated rabbits, the contractile sensitivity of the uterine muscle to spareng was significantly increased by pretreatment with estrogen in large dose but it was markedly decreased by pretreatment with testosterone in small dose. 2. The contractile effect of quinine on the excised uterine muscle of non-castrated rabbits pretreated with estrogen was significantly decreased but that of castrated rabbits pretreated with both estrogen and testosterone were markedly increased comparing with that of the control group. 3. The cholinesterase activity in the uterine muscle of non-castrated rabbits was significantly increased by pretreatment with small dose of estrogen or large dose of testosterone, but that of castrated rabbits was markedly decreased by pretreatment with large dose of estrogen. 4. Na and K contents in the uterine muscle of non-castrated rabbits were markedly increased by pretreatment with both estrogen and testosterone, but that of castrated rabbits was significantly increased by pretreatment with small dose of estrogen. 5. Ca content in uterine muscle of non-castrated rabbits was significantly decreased by pretreatment with both large dose of estrogen and testosterone but increased by pretreatment of testosterone. In castrated rabbits, Ca content was significantly decreased by pretreatment with both estrogen and testosterone. 6. Mg content in the uterine muscle of non-castrated rabbits was markedly increased by pretreatment with estrogen and small dose of testosterone, but that of castrated rabbits was significantly decreased by pretreatment with both large dose of estrogen and testosterone.

• Journal of Gastric Cancer
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• v.13 no.3
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• pp.172-178
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• 2013

Purpose: The aims of this study were as follow: 1) to de scribe the expression status of estrogen receptor-${\alpha}$ and -${\beta}$ mRNAs in five gastric carcinoma cell lines; 2) to evaluate in vitro the effects of $17{\beta}$-estradiol and estrogen receptor antagonists on the proliferation of the cell lines. Materials and Methods: Detection of estrogen receptor-${\alpha}$ and estrogen receptor-${\beta}$ mRNA in five human gastric cancer cell lines (AGS, KATO III, MKN28, MKN45 and MKN74) was made by the reverse transcription-polymerase chain reaction system. To evaluate the effect of $17{\beta}$-estradiol and estrogen receptor antagonists on the proliferation of gastric cancer cell line, the cell lines which expressed both es trogen receptors were chosen and treated with $17{\beta}$-estradiol and estrogen receptor antagonists (methyl-piperidino-pyrazole and pyrazolo [1,5-a] pyrimidine). Cell proliferation was assessed with the methylthiazol tetrazolium test. Results: Estrogen receptor-${\alpha}$ and estrogen receptor-${\beta}$ mRNAs were expressed in three (KATO III, MKN28 and MKN45) and all of the five gastric cancer cell lines, respectively. At higher concentrations, $17{\beta}$-estradiol inhibited cell growth of MKN28, MKN45 and KATO III cell lines. Neither estrogen receptor-${\alpha}$ nor estrogen receptor-${\beta}$ antagonist blocked the anti-proliferative effect of $17{\beta}$-estradiol. Conclusions: Our results indicate that estrogen receptor-${\beta}$ mRNAs are preferentially expressed in gastric cancers and also imply that hormone therapy rather than estrogen receptor blockers may be a useful strategy for the treatment of estrogen receptor-${\beta}$ positive gastric cancer. Its therapeutic significance in gastric cancer are, however, limited until more evidence of the roles of estrogen receptors in the gastric cancer are accumulated.