• Fisheries and Aquatic Sciences
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• 제19권9호
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• pp.41.1-41.7
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• 2016

Background: The transgenic approach using estrogen-responsive regulator in fish has been given much attention as a potential means to detect and/or address estrogen-related aquatic pollutions. In order to address the development stage- and reproduction status-dependent expression patterns of the chgH-rfp transgene (red fluorescent protein transgene driven by choriogenin H promoter) in marine medaka Oryzias dancena, naturally occurring red fluorescent protein (RFP) signals under non-exposed conditions as well as the transgenically induced RFP signals under estrogen-exposed conditions were assayed. Results: Female transgenics begun to show naturally occurring RFP signals from the age of 7 weeks post hatching (WPH) without experimental estrogen exposure. Afterward, these RFP signals in female transgenics became robust with the progress of ovarian maturation. On the other hand, male transgenics did not show any naturally occurring RFP signal under non-exposed conditions irrespective of developmental stages and maturation statue. Upon exposures using estradiol-$17{\beta}$ (E2) and $17{\alpha}$-ethinylestradiol (EE2), RFP signals were significantly induced specifically in the livers of transgenic males. Conclusions: Male chgH-rfp transgenics were able to keep the "off" state of RFP expression during their entire life cycle unless exposed to exogenous estrogens. Owing to their tight regulation capability of estrogen-responsive transgene, transgenesis of chgH-rfp in male marine medaka could offer a useful model system for future ecotoxicogenomic studies regarding estrogenicity-related issues in aquatic and marine environments.

• Korean Journal of Animal Reproduction
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• 제22권1호
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• pp.81-87
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• 1998

This experiment was carried out with 12 Korean native heifers(8~12month old, body weight, 160~240kg) raised at a farm of Chang-Soo Livestock Cooperatives to evaluate the effects of rGH(recombinant growth hormone) on serum concentrations of growth hormone, estrogen, and IGF-I, weight gain, teat volume gain and processing enzyme activity of IGF-I, binding protein III at 28 day intervals. Animals used were injected with 250mg rGH at 14 day intervals from December to Ferbruary in 1994. The significant difference was found in the group of treatment on the 4th week in the endogenous GH(p<.01) and 8th week in estrogen and IGF-I(p<.05) after injectin of rGH in Korean native heifers. There were significant differences between control group and treatment group in weight and teat volume on 8th week after treatment(p<.05). Processing enzyme activity before injection of rGH were low. However, heifers injected with 250mg of rGH showed that processing enzyme activity of IGF binding protein was highly increased throughout the experiment. Present results suggest that injection of exogenous rGH to heifers can increase the growth performance and udder development of Korean native heifers by the endogenous hormonal changes.

• Asian-Australasian Journal of Animal Sciences
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• 제25권8호
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• pp.1145-1152
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• 2012

This experiment was conducted with male chicks to investigate the influence of hormones and nutrients on the development of fatty liver syndrome (FLS) as well as the effects of dietary lipotropic factors on hepatic fat accumulation and lipogenic enzyme gene expression. A total of two-hundred sixteen 4-wk-old Hy-Line male chicks were divided into six groups and fed an experimental diet (T1, low-energy diet with low levels of lipotropic factors; T2, high-energy diet with low levels of lipotropic factors; T3 and T5, low-energy diet with high levels of lipotropic factors; T4 and T6, high-energy diet with high levels of lipotropic factors) for six weeks. The chicks in T5 and T6 groups were treated with intramuscular injections of estradiol benzoate for three days prior to biopsy and clinical analysis of FLS. Chicks treated with estrogen had significantly greater liver weights than untreated chicks. The abdominal fat contents were increased in chicks consuming high-energy diets as compared to those consuming low-energy diets. Treatment with estrogen significantly increased the concentrations of serum cholesterol, triacylglycerol and phospholipid (p<0.05). The hepatic triacylglycerol levels were tenfold higher in the estrogen treated chicks than in the untreated chicks. There were no significant differences in malondialdehyde levels between the treatment groups. Estrogen treatment dramatically increased the levels of fatty acid synthetase, acetyl-CoA carboxylase and ApoB mRNA. The results indicated that treatment with exogenous estrogen in growing male chicks induced hepatic fat accumulation, which might be partially due to increased lipogenic enzyme gene expression.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 한국어업기술학회 2003년도 춘계 수산관련학회 공동학술대회발표요지집
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• pp.156-157
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• 2003

In teleost, vitellogenin (Vtg) is synthesised in the liver in response to estrogens and transported by the blood to the growing oocytes where it is incorporated by micropincytosis (Selman and Wallace, 1982). Generally, Vtg is not induced in normal male fish but male fish are capable of synthesis Vtg in reponse to exogenous estrogen and xenoestrogens. (omitted)

• Asian-Australasian Journal of Animal Sciences
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• 제23권1호
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• pp.13-16
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• 2010

The effect of exogenous administration of tamoxifen (TAM) on hormonal profile and sexual maturity in Indian native Kadaknath (KN) fowl was investigated. Day-old chicks from the same hatch were randomly divided into 15 groups with 20 chicks in each group (5 treatments${\times}$3 replicates). The chicks were placed in battery brooders with wire-mesh floors and reared under uniform husbandry conditions (14 h light/d, 25-32${^{\circ}C}$) on a standard basal diet. At the age of two weeks (wk), birds from the control group ($T_{1}$) were injected with maize oil intramuscularly (I/M), whereas the other four experimental groups $T_{2}$, $T_{3}$, $T_{4}$ and $T_{5}$ were given tamoxifen (I/M) dissolved in maize oil at the rate of 0.5 mg (0.5 TAM), 1.0 mg (1.0 TAM), 2.5 mg (2.5 TAM) and 5.0 mg (5.0 TAM)/kg body weight, respectively, up to 30 wks on every alternate day. At every 6-wk interval, blood samples were collected from nine birds of each treatment group for estimation of estrogen and progesterone. The same birds were sacrificed for determination of the weight of ovary, oviduct, liver and adipose tissue. There was no significant difference in egg production traits except onset of lay and egg number. Low doses of TAM ($T_{3}$) advanced the onset of egg laying by 15 days over the control. Tamoxifen influenced the hormonal profile (estrogen and progesterone) in a dose dependent manner. However, higher doses of TAM suppressed ovary and oviductal growth. From this study, it may be concluded that lower doses of TAM enhanced sexual maturity while higher doses suppressed ovary and oviductal growth.

• Journal of Veterinary Clinics
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• 제16권2호
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• pp.389-396
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• 1999

Pregnant rats were treated at various stages of gestation with prostaglandin analogue, cloprostenol alone or concomitant with HCG to study effects on termination of gestation and plasma estrogen and progesterone. Cloprostenol (90 or 180 mg/kg) was administered alone on 1~3, 4~6, 7~9, 9~11 or 11~13 consecutive days of gestation twice a day and in combination with HCG (50 or 100 IU/day) on days of 1~3 or 7~9 once a day. Rats were autopsied on day 21 of gestation or at 6, 12 or 24 hours after treatment on day 6 or 9, respectively. Cloprostenol was found to be nearly 100% effective in preventing implantation, destroying viable fetuses and causing preimplantation losses, but in early gestation, on days 1-3, there was little effect. And when cloprostenol administered concomitant with HCG, corpora lutea were significantly increased, implantation sites and viable fetuses significantly decreased, and pre-and post-implantation losses significantly increased in most cases. Plasma concentrations of estradiol and progesterone were significantly decreased by administering cloprostenol, and estradiol concentration significantly decreased but progesterone significantly increased by administering of cloprostenol concomitant with HCG. It is suggested that cloprostenol was more effective in terminating pregnancy than a combination of cloprostenol and HCG in the rat.

• Journal of Ginseng Research
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• 제40권3호
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• pp.251-259
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• 2016

Background: Estrogen signaling pathways are modulated by exogenous factors. Panax ginseng exerts multiple activities in biological systems and is classified as an adaptogen. Zearalenol is a potent mycoestrogen that may be present in herbs and crops arising from contamination or endophytic association. The goal of this study was to investigate the impact of P. ginseng, zearalenol and estradiol in tests on spermatozoal function. Methods: The affinity of these compounds for estrogen receptor (ER)-alpha and beta ($ER{\alpha}$ and $ER{\beta}$)-was assessed in receptor binding assays. Functional tests on boar spermatozoa motility, movement and kinematic parameters were conducted using a computer-assisted sperm analyzer. Tests for capacitation, acrosome reaction (AR), and chromatin decondensation in spermatozoa were performed using microscopic analysis. Results: Zearalenol-but not estradiol ($E_2$)- or ginseng-treated spermatozoa-decreased the percentage of overall, progressive, and rapid motile cells. Zearalenol also decreased spontaneous AR and increased chromatin decondensation. Ginseng decreased chromatin decondensation in response to calcium ionophore and decreased AR in response to progesterone ($P_4$) and ionophore. Conclusion: Zearalenol has adverse effects on sperm motility and function by targeting multiple signaling cascades, including $P_4$, $E_2$, and calcium pathways. Ginseng protects against chromatin damage and thus may be beneficial to reproductive fitness.

• Journal of Digestive Cancer Research
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• 제11권2호
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• pp.61-65
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• 2023

Globally, esophageal cancer is the seventh most common cancer, and the male-to-female ratio in esophageal adenocarcinoma (EAC) is significantly imbalanced at 4:1 to 8:1. Obesity, reflux, and smoking are known risk factors for this sex difference; however, fully explaining this remains challenging. Studies have investigated the link between exogenous sex hormones and esophageal cancer occurrence. A meta-analysis revealed a lower risk of EAC in female who had undergone hormone replacement therapy. Androgen-deprivation therapy in patients with prostate cancer was associated with a decreased risk of EAC. Tissue-based studies have reported varied results regarding the relationship between estrogen receptor expression and survival in female patients with esophageal squamous cell carcinoma (ESCC). Circulating hormone studies have suggested that higher testosterone and luteinizing hormone levels decreased EAC risk in men, and free testosterone was inversely correlated in female with ESCC. However, a high androgen-estrogen ratio in male patients with EAC was linked to increased odds of EAC. Sex hormones influence carcinogenesis, affecting cell proliferation, differentiation, metabolism, inflammation, and cell death. The studies were limited by the small sample size and varying hormone measurement methods; thus, future studies with definitive conclusions on the association between esophageal cancer and sex hormones are warranted.

• Journal of Veterinary Clinics
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• 제15권1호
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• pp.83-93
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• 1998

The purposes of the present study were to evaluate the effect of estrone on the prevention of implantation and pregnancy and the concentrations of estradiol and progesterone or sodium and potassium in the plasma or uterine fluid of pregnant rats injected a single dose of 0, 0.1, 0.4 or 1.0 mg on days 5, 9, or 13 of pregnancy. The body weight gains of pregnant rats were significantly decreased in administering estrone on day 5 of pregnancyi no effect obtained on days 9 or 13. Numbers of viable fetuses were significantly decreased and pre- and post-implantation loss increased by administering estrone 0.1, 0.4 or 1.0 mg and numbers of implantation sites significantly increased by administering estrone 0.1 mg but significantly decreased or not occurred by 0.4 or 1.0 mg on day 5 of pregnancy, respectively, but no effect obtained on days 9 or 13. Plasma estradiol concentrations of pregnant rats were significantly increased on 1, 2 or 18 days after treatment with estrone (1.4 or 1.0 mg and 3 days after 0.4 mg on day 5 of pregnancy, respectively. But plasma progesterone concentrations had no effect on the treatment with estrone. Plasma sodium contents were significantly increased on 1 day after treatment with estrone 0.1 or 1.0 mg and 3 days after 0.1 mg on day 5 of pregnancy, respectively, except potassium content were no detectable change. Sodium contents in uterine fluid were significantly increased on 1 day after treatment with estrone 1.0 mg and 3 days after 0.1, 0.4 or 1.0 mg on day 5 of pregnancy, respectively. And potassium contents were significantly increased on 1 or 2 days after treatments with estrone 0.1 mg but significantly decreased on 3 days after 0.4 or 1.0 mg on day 5 of pregnancy, respectively. It is suggested that the prevention of implantation and failure of pregnancy could be induced by treatment with estrone 0.4 mg on day 5 of pregnancy and might be interrelated with changes of plasma estradiol concentration and sodium and potassium contents in uterine fluid.

• Proceedings of the PSK Conference
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.120.2-120.2
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• 2003

Cytochrome P-450 3A4 (CYP3A4) is major enzyme in human liver, the role of this is detoxification and metabolizing more than 50% clinical drugs in use. Expression of CYP3A4 is transciptionally regulated by the Pregnenolone X receptor (PXR), of which human form is Steroid and Xenobiotics receptor (SXR). SXR is activated by wide range of endogenous and exogenous compounds, and then induces CYP3A4 gene expression. In the previous study, it has been known that proximal promoter (-864 to +64) does not response to chemical inducers such as pregnenolone 16a-carbonitrile (PCN), Rifampicin, Estrogen in terms of transcription of CYP 3A4 in cultured cells. (omitted)