• Korean Journal of Animal Reproduction
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• v.26 no.2
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• pp.183-192
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• 2002

The present studies were carried out to examine the effects of exogenous oxytocin(OT) on plasma, uterine and placenta of estradiol-17$\beta$, progesterone, prostaglandin F$_2$$_{\alpha}$ (PGF$_2$$_{\alpha}$), Prostaglandin E$_2$(PGE$_2$) and OT receptor concentrations in pregnant rats. Pregnant rats received an injection of exogenous OT on days 14, 16, 18, 20, 22 of pregnancy and day 1 of postpartum. Concentrations of plasma estradiol-17 $\beta$ after OT injection started to increase after day 18 and peaked on day 22 of pregnancy but decreased on day 1 of postpartum. Plasma progesterone concentrations declined gradually from day 18 of pregnancy and decreased more rapidly until postpartum 1 day. Concentrations of estradiol-17$\beta$in uterine tissues after OT injection were sharply increased from day 20 to 22 of pregnancy and progestrone concentrations were peaked on day 16 and decreased rapidly from day 16 to 20 and maintained the same level until day 1 of postpartum. Uterine concentrations of PGF$_2$$_{\alpha}$ and PGE$_2$increased gradually until day 20 and peaked on day 22 of pregnancy but showed a marked decrease on day 1 of postpartum. Concentrations of PGF$_2$$_{\alpha}$ in placental tissues increased rapidly from day 14 of pregnancy and decreased sharply on day 1 of postpartum. Concentrations of PGE$_2$increased gradually after day 14 and peaked on day 20 of pregnancy. The concentration of OT receptor in uterus was significantly elevated from day 20 and rose to maximum on day 22 of pregnancy. These findings show that OT suppress the concentration of progestrone and stimulate productions of estradiol-17 $\beta$, PGF$_2$$_{\alpha}$, PGE$_2$ and oxytocin receptor concentrations in pregnant rats.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.6
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• pp.2161-2166
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• 2015

Estrogen receptors (ERs) are steroid receptors located in the cytoplasm and on the nuclear membrane. The sequence similarities of human $ER{\alpha}$, mouse $ER{\alpha}$, rat $ER{\alpha}$, dog $ER{\alpha}$, and cat $ER{\alpha}$ are above 90%, but structures of $ER{\alpha}$ may different among species. Estrogen can be agonist and antagonist depending on its target organs. This hormone play roles in several diseases including breast cancer. There are variety of the relative binding affinity (RBA) of ER and estrogen species in comparison to $17{\beta}-estradiol$ (E2), which is a natural ligand of both $ER{\alpha}$ and $ER{\beta}$. The RBA of the estrogen species are as following: diethyl stilbestrol (DES) > hexestrol > dienestrol > $17{\beta}-estradiol$ (E2) > 17- estradiol > moxestrol > estriol (E3) >4-OH estradiol > estrone-3-sulfate. Estrogen mimetic drugs, selective estrogen receptor modulators (SERMs), have been used as hormonal therapy for ER positive breast cancer and postmenopausal osteoporosis. In the postgenomic era, in silico models have become effective tools for modern drug discovery. These provide three dimensional structures of many transmembrane receptors and enzymes, which are important targets of de novo drug development. The estimated inhibition constants (Ki) from computational model have been used as a screening procedure before in vitro and in vivo studies.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2004.10a
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• pp.85-86
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• 2004

• Journal of Embryo Transfer
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• v.21 no.2
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• pp.109-119
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• 2006

This study was conducted to examine relationship between vaginal cytology and reproductive hormones during the estrous cycle and to provide basic data to estimate for ovulation time and optimal mating time in 6 beagle dogs The duration of proestrus, estrus and diestrus were $8.5{\pm}1.4,\;10.0{\pm}1.4\;and\;54.0{\pm}2.8$ days at pregnant respectively, and $7.9{\pm}2.1,\;9.5{\pm}0.7\;and\;62.0{\pm}11.3$ days at non-pregnant respectively. The duration of interestrous intervals were $246.2{\pm}24.5$ days at pregnancy, and $175.3{\pm}34.5$ days at non-pregnancy. The duration of interestrous intervals at pregnancy was longer than that of non-pregnancy. A characteristic features of vaginal cytology during the estrous cycle were the high proportion of superficial cell, anuclear cell and erythrocyte in proestrus and estrus, parabasal cell, small intermediate cell and leukocyte in diestrus, and parabasal cell and small intermediate cell in anestrus, respectively. Cornification index (CI) in proestrus and estrus were significantly higher than that of CI in diestrus and anestrus. Plasma progesterone concentration was below 1.0 ng/ml at the first day of vulval bleeding at pregnancy and non-pregnancy, and then it was above 2.0 ng/ml at Day -2 in all bitches. When plasma progesterone concentration was first increased above 4.0 ng/ml, it was the second day after the first day of male acceptance. Plasma progesterone concentration showed above 40 ng/ml on Day $20{\sim}22$ in all bitches, and then it was gradually decreased until Day 35. Plasma progesterone concentration at pregnancy was higher than that of non-pregnancy from Day 35 to Day 63. Plasma estradiol-$17\;{\beta}$ concentration was above 9.0 pg/ml at the first day of vulval bleeding, and it showed 26.4 pg/ml on Day -2. When it was timed from the first day of male acceptance (Day 0), plasma estradiol-$17{\beta}$ concentration showed a peak on Day 0 and plasma progesterone concentration was first increased above 4.0 ng/ml on Day 2 which was the third day after plasma estradiol-$17{\beta}$ peak. CI was first increased above 80 and 90% on Day -1 and Day 1, respectively. CI was maintained above 80% from Day -1 to Day 8 (10 days) and above 90% from Day 1 to Day 6 (6 days), respectively. CI was maintained above 80% from Day 0 to Day 8 (9 days) and above 90% from Day 1 to Day 6 (6 days), respectively. Plasma progesterone concentration was first increased above 4.0 ng/ml on the second day after the day which CI was first increased above 90%. In conclusion, beagle bitches ovulated on the second day after the day which CI was first increased above 90% and on the day which plasma progesterone concentration was first increased 4.0 ng/ml, and it was estimated that the optimal mating time was the day which the second day after CI was first increased above 90% and plasma concentration was between $2{\sim}25ng/ml$. The measurement of plasma progesterone was used to determine of and accurate ovulation time and the optimal mating time, but vaginal cytology is low-priced and simple method to estimate estrous cycle, optimal mating time and ovulation time.

• Bulletin of the Korean Chemical Society
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• v.30 no.9
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• pp.2125-2128
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• 2009

• Biomedical Science Letters
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• v.15 no.3
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• pp.179-185
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• 2009

In our previous report, we showed that $PPAR{\gamma}$ does not influence adipogenesis in females with functioning ovaries, indicating that $PPAR{\gamma}$ activity on adipogenesis is associated with sex-related factors. Among the sex-related factors, estrogen has been recognized as a major factor in inhibiting adiposgenesis in females. Thus, we hypothensized that $17{\beta}$-estradiol (E) inhibits 3T3-L1 cell adipogenesis by preventing $PPAR{\gamma}$ activity. E decreased triglyceirde accumulation in differentiated 3T3-L1 cells compared with control group. E also decreased the expression of $PPAR{\gamma}$ mRNA as well as $PPAR{\gamma}$ dependent adipocyte-specific genes, such as adipocyte fatty acid binding protein and tumor necrosis factor $\alpha$. In addition, E not only decreased luciferase reporter activity by $PPAR{\gamma}$, but also transfection of estrogen receptor $\alpha$ ($ER{\alpha}$) or $ER{\beta}$ led to decreases in $PPAR{\gamma}$ reporter gene activation. Moreover, E-activated ERs significantly decreased the luciferase reporter gene activation induced by $PPAR{\gamma}$ transfection, suggesting that estrogen-activated ERs inhibit $PPAR{\gamma}$-dependent transactivation. Accordingly, our results demonstrate that E inhibits the action of $PPAR{\gamma}$ on adipogenesis through E activated ER, providing evidence that lack of estrogen may potentiate $PPAR{\gamma}$ action on adipogenesis.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.3
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• pp.411-416
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• 1993

We assessed effects of ovine luteinizing hormone (oLH) and follicle-stimulating hormone (oFSH) on the granulose and theca layers from the four largest follicles, $F_1-F_4$ of hens which had been hypophysectomized 12 h before expected ovulation. Ovine LH (0.4 mg), oFSH (0.4 mg) or oLH in combination with oFSH (0.4 mg each) was injected intravenously 6 h after hypophysectomy. Progesterone, testosterone and $estradiol-17{\beta}$ levels of the granulose and theca layers which were removed 6 h after hormone injection, were measured by radioimmunoassay. Progesterone contents of $F_1-F_3$ granulosa layer at 12 h after hypophysectomy were much lower than those of control hens. This reduced progesterone level was restored partially by the injection of oLH alone for $F_1$, while no follicles responded to oFSH treatment. In contrast, the injection of oLH in combination with oFSH resulted in high progesterone content of the granulose layer from all four follicles. Progesterone content of the theca layer was negligible in all treatments. Simultaneous injection of oLH and oFSH also elevated $estradiol-17{\beta}$ level accumulating in the theca layer from all follicles, of which much higher concentrations of $estradiol-17{\beta}$ were observed when comparison were made to each of their corresponding controls. No appreciable change in testosterone contents of two layers was observed in the present experiments. These results suggest that oFSH augments function of oLH to stimulate the production of progesterone in the granulose layer and $estradiol-17{\beta}$ in the theca layer.

• Journal of Korean Society of Water and Wastewater
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• v.26 no.2
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• pp.313-319
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• 2012

This study investigated the relative degradation of commonly known endocrine-disrupting compounds such as bisphenol A (BPA) and 17${\beta}$-estradiol (E2) using ultrasound (US) and pulsed ultraviolet (PUV) in water. The removal efficiency of BPA and E2 was determined as a function of generating power and $H_{2}O_{2}$ production. The ultrasound and PUV irradiation of the aqueous solution was performed in 3 L and 90 L stainless reactor at a constant temperature of $20^{\circ}C$ with an applied power of 200 W and 2000 W, respectively. The removal of BPA and E2 by US and PUV varied with catalysts. The experiments were conducted under the following conditions: total operating time, 30 min; initial concentration, 1 uM. In the case of E2 (10 min), % removal was 92.5/95.8/87.6/82.4, while % removal of BPA (10 min) was 62.3/82.3/91.1/67.0/64.3 in various conditions (PUV, $PUV+H_2O_2$, PUV+wire mesh, $PUV+TiO_2$ coated wire mesh), respectively.

• Korean Journal of Veterinary Research
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• v.30 no.3
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• pp.349-354
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• 1990

The effects of $PGF2{\alpha}$ on the conception rate and the plasma levels of estradiol-$17{\beta}$ and progesterone of anestrus Cheju mares were investigated at the breeding and non-breeding seasons. The results obtained from this studies are as follows; 1. The durations of the estrus and diestrus after $PGF_2{\alpha}$ treatment persisted shorter than control cycle (p<0.05), but ovulation time was fast. 2. The levels of estradiol-$17{\beta}$ and progesteron before $PGF_2{\alpha}$ treatment showed 103.8pg/ml, 8.0ng/ml in breeding season and 72.8pg/ml, 4.7ng/ml in non-breeding season, respectively. 3. The levels of estradiol-$17{\beta}$ rose to 115.4~154.0pg/ml, and 90.8~27.0pg/ml from 2nd to 6th day after the treatment of $PGF_2{\alpha}$, in breeding and non-breeding seasons, respectively, while progesterone level dropped to 1ng/ml with the sign of estrus and at 8th day rose in breeding season (p<0.05). 4. Of thirty anestrus mares investigated for $PGF_2{\alpha}$ administration, 87.5% showed estrus on an average of 3.8 days after treatment and the conception rate was 62.5% in breeding season, but the estrus and conception rates dropped 40% and 20% in non-breeding season, respectively.

• Clinical and Experimental Reproductive Medicine
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• v.21 no.2
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• pp.191-200
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• 1994

The influence of hypoxanthine and ovarian steroids on the meiotic maturation process of mouse oocytes was investigated for the qualified application of culture medium in in vitro fertilization(IVF). Mouse oocytes were cultured in hypoxanthine and various ovarian steroids(progesterone, estradiol-17${\beta}$ and testosterone) and their effects on the oocyte maturation had been observed. When mouse oocytes were cultured in the various concentration(1-4mM) of hypoxanthine, meiotic maturation of cumulus cell-enclosed oocytes was inhibited by presence itself, which was a dose-dependent effect in meiotic arrest of mouse oocytes. The presence of progesterone, estradiol-17${\beta}$ and testosterone have made the mouse oocyte mature properly. Meanwhile maturation of cumulus cell-enclosed oocyte was severely inhibited by 3 hoursculture in the media of progesterone supplemented with hypoxanthine. However the continuous presence lasting 24 hours of progesterone even supplemented with hypoxanthine had got rid of the inhibition of oocytes maturation. Not only estradiol-17${\beta}$ supplemented with hypoxanthine but also testosterone supplemented with hypoxanthine exert the severe inhibition of the maturation of cumulus cell-enclosed oocytes for 3-hours culture. However the continuous presence lasting 24 hours of estradiol-17${\beta}$ and testosterone even supplemented with· hypoxanthine had relieved the inhibition of oocytes maturation. These results make us suggest that hypoxanthine inhibits the mouse oocyte maturation, particularly markedly in conjunction with ovarian steroids for short period, which indicated some sort of the synergistic inhibitory retationship between the ovarian steroids and hypoxanthine.