• Korean Journal of Animal Reproduction
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• v.15 no.3
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• pp.161-172
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• 1991

This study was conducted to research the endocrine mechanisms of postpartum anestrus and determine if the morphology of the CL could be related to function in Korean native goats. At parturition 48 goats were assigned to a nonsuckled group and a suckled group. Serum concentrations of luteinizing hormone(LH), follicle stimulating hormone(FSH), prolactin(PRL), estradiol-17$\beta$(E2) and cortisol were measured at various times after parturitionin the goats. The corpora lutea of pregnancy were examined by a light microscope on the 6th hour and the first, 3rd, 10th, 11th, and 21st days after parturition. The results were summarized as follows : Mean serum LH concentrations were lower after parturition in all treatments and increased gradually with the intervals after parturition(P<0.01). These values did not differ between groups. The levels of serum FSH were lower after parturition and tended to increase gradually between 2 and 21 days. The levels of serum FSH are not significantly different between the groups of goats. Two days after kidding mean levels of serum PRL began to fall in nonsuckling goats but increased in suckling goats. During 3 weeks serum PRL concentrations were different between nonsuckling and suckling goats(P<0.01). Three days after parturition the levels of serum E2 decreased in all treatments. From parturition to day 21 serum E2 concentrations were greater in nonsuckling than in suckling goats(P<0.01). At the sixth hour after parturition the structure of the CL was well preserved. At days 1 and 3 the blood vessels were sparcely distributed, whereas, at days 1 and 3 the blood vessels were sparcely distributed, whereas, at days 10, 11 and 21 tortuous larger vessels with thick walls were observed on the luteal tissue. At days 1, 3, 10, 11 and 21 after parturition the CL of pregnancy showed degeneration and the proportion of tissue occupied by intercelluar substances increased at days 21 postpartum. In conclusion, the present study has shown that regression of the CL of pregnancy is accelerated in the period after parturition and effectively completed within three weeks postpartum.

• Korean Journal of Food Science and Technology
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• v.32 no.4
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• pp.964-969
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• 2000

Di-(2-ethylhexyl) adipate(DEHA) has been used extensively as a plasticizer in the manufacture of plastic products such as PVC films. Though, phthalate esters plasticizers have been known to induce endocrine system-mediated responses, few studies have been conducted for the screening of estrogenic activity of DEHA, an adipate plasticizer. This study was initiated to evaluate the estrogenic activity of DEHA by in vitro E-screen assay and in vivo uterotrophic assay. MCF-7 human breast cancer cells were treated with $DEHA(5{\times}10^{-9}{\sim}5{\times}10^{-4}\;M)$, for 144 hr, and cell proliferation was determined by sulforhodamine B(SRB) assay. DEHA dissolved in corn oil was administered subcutaneously to ovariectomized(OVX) female Sprague-Dawley rats at dosage levels of 0, 2, 20 and 200 mg/kg/day for three consecutive days. Rats were sacrificed 24 hr after final treatment and vagina and uterus(wet and blotted) weights were obtained. E-screen assayed DEHA did not generate cell proliferation at treated concentrations$(5{\times}10^{-9}{\sim}5{\times}10^{-4}\;M)$, whereas 17 ${\beta}-estradiol$(E2), the positive control, induced cell proliferation at low concentrations$(5{\times}10^{-14}{\sim}5{\times}10^{-9}\;M)$. In the uterotrophic assay, DEHA did not change vagina and uterus(wet and blotted) weights at dosage levels up to 200 mg/kg/day treatment. These results demonstrated that DEHA did not exhibit the estrogenic activity as determined by in vitro E-screen assay and in vivo uterotrophic assay.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.8
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• pp.4003-4007
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• 2016

Long interspersed elements-1s (LINE-1s) are dispersed all over the human genome. There is evidence that hypomethylation of LINE-1s and levels of sex steroids regulate gene expression leading to cancer development. Here, we compared mRNA levels of genes containing an intragenic LINE-1 in breast cancer cells treated with various sex steroids from Gene Expression Omnibus (GEO), with the gene expression database using chi-square analysis (http://www.ncbi.nlm.nih.gov/geo). We evaluated whether sex steroids influence expression of genes containing an intragenic LINE-1. Three sex steroids at various concentrations, 1 and 10 nM estradiol (E2), 10 nM progesterone (PG) and 10 nM androgen (AN), were assessed. In breast cancer cells treated with 1 or 10 nM E2, a significant percentage of genes containing an intragenic LINE-1 were down-regulated. A highly significant percentage of E2-regulated genes containing an intragenic LINE-1 was down-regulated in cells treated with 1 nM E2 for 3 hours (p<3.70E-25; OR=1.91; 95% CI=2.16-1.69). Similarly, high percentages of PG or AN-regulated genes containing an intragenic LINE-1 wwere also down-regulated in cells treated with 10 nM PG or 10 nM AN for 16 hr (p=9.53E-06; OR=1.65; 95% CI=2.06-1.32 and p=3.81E-14; OR=2.01; 95% CI=2.42-1.67). Interestingly, a significant percentage of AN-regulated genes containing an intragenic LINE-1 was up-regulated in cells treated with 10 nM AN for 16 hr (p=4.03E-02; OR=1.40; 95% CI=1.95-1.01). These findings suggest that intragenic LINE-1s may play roles in sex steroid mediated gene expression in breast cancer cells, which could have significant implications for the development and progression of sex steroid-dependent cancers.

• 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.

• Journal of Embryo Transfer
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• v.30 no.2
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• pp.83-89
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• 2015

The sexual maturation occurred by the changes of steroid hormones was known to sex-dependently and/or age-dependently regulate the lipid metabolism in various animal species. Our current study demonstrates that lipid and its functional fatty acids can be changed depending on the status of sexual maturation. Of the functional fatty acids, ${\gamma}$-linolenic acid (GLA; 18:3n-6) is an important factor for maintaining human health. The purpose of our study was to investigate the level of GLA in mice with different stages of sexual maturation. To this end, the longissimus muscle (LM) of immature (3-week-old) and mature (7-week-old) female mice was analysed for the fatty acid composition by gas chromatography. Furthermore, both gene and protein level of ${\Delta}6$ desaturase (FADS2) which is involved in GLA metabolism by real time PCR and Western blotting, respectively. Mature females showed greater (P<0.05) serum $17{\beta}$-estradiol (E2) level and LM GLA contents than immature group. The mRNA and protein levels of FADS2, which converts precursor linoleic acid into GLA, were higher (P<0.05) in mature female mice than in immature mice. In conclusion, these results show that sexual maturation of female mice induces GLA and FADS2 contents in LM.

• Development and Reproduction
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• v.16 no.4
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• pp.279-287
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• 2012

We investigated the changes in plasma sex steroid hormones, testosterone (T), estradiol-$17{\beta}$ ($E_2$), 17,$20{\beta}$-dihydroxy-4-pregnen-3-one ($17{\alpha}20{\beta}P$), 11-ketotestosterone (11KT) and cortisol levels from ribbed gunnel, Dictyosoma burgeri in associated with annual reproductive cycle. The gonadosomatic index (GSI) of females increased from November, peaked in February and decreased rapidly from March. The GSI of males also increased from November, peaked in January and then decreased gradually. In females, $E_2$ levels increased and remained high from December to February. The levels of T showed a similar tendency and correlated ($r_s$=0.898, p<0.01) with $E_2$ levels. The levels of $17{\alpha}20{\beta}P$ increased rapidly in February ($4.78{\pm}1.01ng/ml$) and peaked in July ($5.08{\pm}0.65ng/ml$). Cortisol level was peaked in March and correlated with $17{\alpha}20{\beta}P$ levels ($r_s$=0.696, p<0.01). In males, the levels of T was peaked in January and then decreased rapidly. The levels of 11KT were remained high from October to January. On the other hand, the levels of $17{\alpha}20{\beta}P$ fluctuated during reproductive cycle. These results suggest that plasma sex steroids in ribbed gunnels have annual periodicity, and that cortisol may involve in maturation of females.

• Nutrition Research and Practice
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• v.8 no.3
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• pp.292-296
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• 2014

BACKGROUND/OBJECTIVES: This study was conducted to assess the potential of St. John's Wort (Hypericum perforatum) to prevent obesity and abnormalities in lipid metabolism induced by ovariectomy in a rat model without stimulatory activity on uterus. MATERIALS/METHODS: Ovariectomized (OVX) rats were treated for 6 weeks with 70% ethanol extracts of Hypericum perforatum [HPEs: whole plant (WHPE) and flower and leaves (FLHPE)], ${\beta}$-estradiol-3-benzoate at a dose of $50{\mu}g/kg/day$ (E2) or vehicle (distilled water). RESULTS: As expected, OVX increased body weight gain and adiposity and showed higher food efficacy ratio. OVX also increased the serum cholesterol as well as insulin resistance, while reducing uterus weight and uterine epithelial proliferation rate. HPEs (WHPE and FLHPE) showed estrogen-like effect on body weight gain, adipose tissue weight and food efficacy ratio in OVX rats. HPEs prevented hypercholesterolemia induced by OVX more effectively than E2. E2 increased uterus weight and epithelial proliferation rate in OVX rats, while HPEs maintained them at the level of the sham-operated animals. CONCLUSIONS: Our finding demonstrates that HPEs can be considered as an effective agent to prevent OVX-induced obesity without stimulatory activity on uterus.

• Journal of Aquaculture
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• v.16 no.4
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• pp.267-272
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• 2003

This study investigated sex determination through serum steroid hormone level and compared hematological characteristics of one-year old cultured eels, Anguilla japonica. Four different groups were divided with total length at 40∼45, 45∼50, 50∼55, and 55∼60 cm. Males dominated eels of 40∼50 cm in total length group, while females dominated eels of more than 50 cm. All females and males were immature. Hematocrit levels of males (total length: 40∼50 cm) were higher than those of females (total length: 50∼60 cm). Hemoglobin content also differed between males and females. Glutamate oxaloacetate transaminase (GOT) levels of 40∼45 cm males tended to be higher (157$\pm$3.46 IU/L) than that of other sized males, but there were no significant differences between groups (P<0.05). The highest GOT levels were found in of 55∼60 cm females (148$\pm$3.46 IU/L) compared with that of other female groups (P<0.05). Glutamate pyruvate transaminase (GPT) levels of males and females in the 55∼60 cm size range was significantly higher thanothers (P<0.05). The result of this study indicated steroid hormone content of males and females were very low, but testosterone (T) and estradiol-17$\beta$, (E2) contents of females were higher than those of males. For further research of sex determination in cultured eels, it needs to investigate in more defined body length.

• Development and Reproduction
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• v.13 no.4
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• pp.353-362
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• 2009

GnRH and its receptor are known to express locally in the ovary and to regulate the ovarian function by affecting on granulosa and lutein cells. It has been reported that GnRH directly causes apoptosis in the granulosa and lutein cells of the ovary. However, whether the apoptosis of the cells by GnRH is recovered by FSH as an anti-apoptotic factor is not yet known. In this study, we evaluated the apoptosis and the production of progesterone $(P_4)$ and estradiol $(E_2)$ after treatment with 5, 50, and 100 ng/$m\ell$ GnRH and 1 IU/ml FSH in the granulosa-lutein cells that are obtained during oocyte-retrieval for IVF-ET. Results of DNA fragment analysis and TUNEL assay demonstrated that DNA fragmentation and the rate of apoptotic cells were increased in a dose-dependent manner showing a significant increase in the cells treated with 100 ng/$m\ell$ GnRH. In addition, we found that FSH suppresses the apoptosis of the cells induced by GnRH. In the results of chemiluminescence assay for $P_4$ and $E_2$, $P_4$ production was decreased by GnRH treatment, whereas $E_2$ production was not changed. We also demonstrated that FSH inhibits the suppressive effect of GnRH on $P_4$ production as the result of apoptosis. The present results suggest that GnRH agonist using in ovarian hyperstimulation protocol might induce the dysfunction of the ovary, but its function could be recovered by FSH. These results also will be expected to use as the basic data to elucidate the physiological role of GnRH and to develop new ovarian hyperstimulation protocols for IVF-ET.

• Development and Reproduction
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• v.13 no.4
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• pp.329-339
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• 2009

Cortisol is present in high concentration in the ovary and its receptor is expressed in the ovarian cells. Moreover, cortisol is known to have a role in steroid synthesis and cell metabolism in human granulosa and lutein cells. However, little is known of the role of cortisol presenting in high concentration in the follicles after LH surge on the granulosa-lutein cells. Therefore, the this study we evaluated the apoptosis and the production of progesterone $(P_4)$ and estradiol $(E_2)$ in the granulosa-lutein cells that are obtained during oocyte-retrieval after treatment with 5, 50, and $500{\mu}g/m\ell$ cortisol and 1 IU/$m\ell$ FSH. Results of DNA fragment analysis and TUNEL assay demonstrated that DNA fragmentation and the rate of apoptotic cells were increased in a dose-dependent manner showing a significant increase in 50 and $500{\mu}g/m\ell$ cortisol treated cells. We found, however, that FSH did not suppress the apoptosis of the cells induced by cortisol. In the results of chemiluminescence assay for $P_4$ and $E_2$, $P_4$ production was decreased by cortisol treatment, whereas $E_2$ was not changed. We also demonstrated that FSH did not inhibit the suppressive effect of GnRH on $P_4$ production as the result of apoptosis. The present study suggests that cortisol of high concentration could cause the apoptosis of human granulosa-lutein cells by suppressing the production of $P_4$. However, we need more studies to elucidate the mechanism by which cortisol induces apoptosis in human granulosa-lutein cells in view of the fact that our results are inconsistent with previous reported data.