• Ocean and Polar Research
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• v.32 no.4
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• pp.369-377
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• 2010

To characterize ecotoxicological responses to a natural estrogen, $17{\beta}$-estradiol, we evaluated the life-history of the parental ($F_0$) and first generation ($F_1$) of the harpacticoid copepod, Tigriopus japonicus sensu lato. We evaluated the survival of nauplii and copepodites, the number of days until the emergence of copepodites and adult males, the sex ratio, brooding success, and the first brooding day of adult females. No significant differences in the survival rate were noted in response to treatments with different concentrations of $17{\beta}$-estradiol. However, $17{\beta}$-estradiol induced developmental delay and skewed the sex ratio toward males. Copepod development was delayed significantly in the 0.1 and $1\;{\mu}g\;l^{-1}$ $17{\beta}$-estradiol treatment groups relative to the control group, with a more pronounced delay in the $F_1$ group. Body length and biomass were significantly smaller in the $17{\beta}$-estradiol treated groups than in the controls. The male emergence of T. japonicus s.l. was very high in the 10 and $30\;{\mu}g\;l^{-1}$ $17{\beta}$-estradiol treatment group. Furthermore, exposure to $17{\beta}$-estradiol resulted in morphological deformities such as shrinking and swelling of the urosome, twisted setae of the caudal rami, setal loss of swimming legs, abnormal segmentation of antennules, and dwarfism.

• Clinical and Experimental Reproductive Medicine
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• v.7 no.1_2
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• pp.3-10
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• 1980

Pituitary gonadotropes, as target cells, exhibit cyclic changes in terms of LH and FSH release in synchrony with the estradiol levels. The ultimate release is determined by the relative size of the two pools of gonadotropins, which is regulated by the two controllers: LH-RH and estradiol. LH-RH appears to serve as a primary drive on the gonadotrope, stimulating gonadotropin synthesis, storage, and release. Estradiol amplifies the action of LH-RH and induces the development of a self-priming effect of LH-RH except that it impedes LH-RH mediated gonadotropin release. Negative and positive feedback action of estradiol is revealed to operate by different mechanisms. The pituitary capacity increases severalfold from early to late follicular phase, which is considered to be prerequisite for the development of mid-cycle surge. CNS-hypothalamic dopamine, norepinephrine, and prostaglandins, as well as LH-RH, are involved in the negative and positive feedback effects of estradiol. The possible mechanisms in the triggering of LH-RH release for the initiation of midcycle LH-RH surge are considered.

• Journal of Veterinary Clinics
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• v.31 no.1
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• pp.25-30
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• 2014

This study tested the hypothesis that the priming effects of progesterone on the timing of the LH surge induced by exogenous estradiol are more potentiated the negative feedback actions of progesterone on LH secretion by the existence of estradiol. In previous studies, the time interval from estradiol infusion until the peak of LH surge was gradually and significantly extended by the different levels of progesterone treated before estradiol infusions. Longterm ovariectomized Shiba goats that had received implants of estradiol capsules (Day 0) and three different progesterone silastic packet inducing follicular, subluteal and luteal levels of progesterone were divided into three groups such as non-P, low-P and high-P group. Blood samples were collected daily throughout the experiment for the analysis of gonadal steroid hormone levels. On Day 7, all devices of progesterone and estradiol packets were removed but estradiol capsules were maintained during the experiment, and blood samples were collected at 1 hr interval for 12 h from the time of progesterone removals to determine peripheral changes of estradiol and progesterone concentration. Then all animals were infused estradiol on the Day 7 after 13 h from the removals of progesterone devices with a peristaltic pump into jugular vein at a rate of 3-6 ${\mu}g/h$ for 36 h. For analysis of peripheral LH and estradiol concentration, blood samples were collected via another jugular vein at 2 h intervals for 52 h (from 4 h before the start of estradiol infusion to 48 h after the start of estradiol infusion). In all animals of the three groups treated with estradiol infusion, an LH surge was expressed but the peak time of LH surge was different. This time interval was not extended by the different levels of progesterone treated before estradiol infusions and the difference was not significant during this interval between the Low P and the High P groups. Progesterone pretreatment may contribute to regulating the neural system that is responded by estradiol, and estradiol existence potentiates the negative feedback effect of progesterone on GnRH/LH surge-generating system.

• Journal of Acupuncture Research
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• v.15 no.2
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• pp.29-41
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• 1998

The effect of Cervi Cornu Parvum aqua-acupuncture on serum levels of sex hormone was investigated in ovariectomized rats. Water extract of Cervi Cornu Parvum was daily injected for 30 days at points in rats corresponding to bilateral Taixi (Ki. 3) points of human and non-point at root of tail after ovariectomy, respectively. Serum levels of estradiol, testosterone, progesterone, LH and FSH were measured at 2 and 4 weeks after aqua-acupuncture treatment, respectively. Compared with ovariectomized rats, significant increase of estradiol and progesterone and significant decrease of FSH and LH were elicited at 2 and 4 weeks after aqua-acupuncture treatment. Aqua-acupuncture treatment at non-point did not produce any remarkable effect. These findings suggest aqua-acupuncture may restore dysfunction of hypothalamic-pituitary-ovarian axis, associated with a significant increase of serum estradiol level in ovariectomized rats.

• Journal of Aquaculture
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• v.4 no.2
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• pp.97-110
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• 1991

This study was undertaken to understand the seasonal changes of hormone levels such as luteinizing hormone (LH), follicle stimulating hormone (FSH) and estradiol-$17{\beta}$, serum components such as albumin, total protein and triglycerides, and GSI of rainbow trout (Onco-rhynchus mykiss) under the normal-light circumstances. LH levels were the highest in November whereas FSH levels were decreased progressively from October to February. Serum GTH, such as LH and FSH, levels were low immediately after egg-stripping and were significantly increased in the summer in association with the initiation of vitellogenesis. Serum albumin, total protein, and triglycerides were significantly increased in August in association with initiation of vitellogenesis and were peak in November prior to egg-stripping. Oocyte growth, measured by oocyte diameter and GSI, was significantly increased in August and showed the highest value in January. Correlation coefficients of serum LH with FSH and estradiol-$17{\beta}$ were +0.844 and +0.947, respectively. Correlation coefficients of estradiol-$17{\beta}$ with albumin and total protein were +0.634 and +0.859, respectively. Correlation coefficients of serum estradiol-$17{\beta}$ with triglycerides and GSI were +0.673 and +0.694, respectively. Probably by positive feedback mechanism, LH, FSH and estradiol-$17{\beta}$ appeared to stimulate to liver to secrete albumin, total protein and triglycerides for vitellosenesis.

• Journal of Embryo Transfer
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• v.3 no.1
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• pp.13-23
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• 1988

These studies were undertaken to examine the interaction of tamoxifen with sex steroid hormones in rat uterine activity. The uterine wet weights of the immature Tat uterus were examined after the administration of estradiol-l7$\beta$(1$\mu$g), tamoxifen(50$\mu$g), progesterone(lmg). The uterotropic activity in immature ovariectomized rats was observed under various treatment conditions following pretreatment with above drugs. The results obtained were as follows:1) Tamoxifen produced significant increase (p <0.01) in uterine wet weight compared with control group, although the increase was not as great as that seen with estradiol-17$\beta$. Administration of estradiol-17$\beta$ together with tamoxifen inhibited significantly the increase of uterine wet weight by estradiol-17$\beta$ (p < 0.01). Coadministration of progresterone with tamoxifen partly blocked the increase of tamoxifen-induced uterine wet weights by progesterone. 2) Estradiol-17$\beta$after the estradiol-17$\beta$ pretreatment discontinued the declining uterine wet weights due to the absence of estrogen support, but uteri continued to increase in weight if daily estradiol-17 $\beta$ was maintained. Administration of tamoxifen on the fourth day of estradiol-17$\beta$ treatment reduced uterine wet weights within 24 hours, and the weights continued to decline with additional tamoxifen. 3) The modest growth of the uterus induced by three daily injections of 5Opg tamoxifen remained stable for five days, with or without additional tamoxifen treatment. Coadministration of tamoxifen with estradiol17$\beta$ increased slightly the increase of uterine wet weight by tamoxifen. Coadministration of tamoxifen with progesterone inhibited the increase of uterine wet weight by tamoxifen. 4) The modest growth of the uterus induced by three daily injections of lmg progesterone reduced uterine wet weight to the control level for five days. Commencement of tamoxifen or estadiol-17 $\beta$ injections on the fourth day of progesterone treatment rapidly elevated uterine wet weight.

• Clinical and Experimental Reproductive Medicine
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• v.40 no.3
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• pp.115-121
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• 2013

Objective: Letrozole and estradiol valerate are used to treat some hormonally-responsive symptoms and also in modeling of the polycystic ovary syndrome. However, the stereological analysis of the ovary has received less attention. Estimation of the whole ovary volume using the Cavalieri method can be applied in any orientation desired, but estimation of the mean volume of the oocytes requires isotropic uniform random sectioning. Here, a combined method was developed for estimating the parameters. To our knowledge, no comparison has been made of the effects of letrozole and estradiol on the ovary. Methods: Sixty rats were divided into 4 groups receiving estradiol (4 mg/kg), olive oil, letrozole (1 mg/kg), or normal saline. After 21 days, their ovaries were studied. Results: Relative to the control group, the total volume of the ovary and the cortex increased in the letrozole-treated and estradiol-treated rats. In addition, the number of the preantral, antral, and granulosa cells decreased by 43% to 56% in the letrozole- and estradiol-treated rats. On average, a 19% increase was observed in the atretic oocytes of the letrozole-treated and estradiol-treated rats, but the mean oocyte volume decreased by 29% to 44% in letrozole- and estradiol-treated rats. Furthermore, the letrozole-treated rats showed a 5-fold and 7-fold increase in the volume of the cysts and corpus luteum, respectively. A 3-fold increase was found in the volume of both the cysts and corpus luteum in the estradiol group. Conclusion: The structural changes of the ovary were most pronounced in the letrozole-treated animals.

• Journal of Community Nutrition
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• v.7 no.1
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• pp.29-35
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• 2005

It has been suggested that dietary fat increases the risk of breast cancer by elevating serum estrogen concentrations. However, studies on a relationship between fat intake and breast cancer risk have shown contradictory results, possibly because the levels of fat intake in study populations were too high to observe differences. Also, the effect of other dietary factors may present. The present study was performed to investigate the relationship between diet and estrogen metabolism in premenopausal women whose usual fat intake is relatively low compared to their western counterparts. Twenty lacto-ovo vegetarians (LOV) and twenty omnivores participated in the study. Three day food records including a Saturday or a Sunday were used to estimate nutrient intake. Serum lipids, estradiol, sex-hormone binding globulin, and urinary estradiol were measured. Study results showed $24.8\%$ and $20.9\%$ of energy intake were provided from fat in omnivorous and LOV subjects, respectively. Serum and urinary levels of estradiol were two times higher in omnivores. Fat intake was not related to either serum estradiol nor urinary estradiol when the Spearman correlation coefficient analysis was performed. Carbohydrate, total dietary fiber and soluble dietary fiber intakes were negatively related to serum estradiol concentration. Legumes, vegetables and fruit consumption showed significantly negative relationships with both serum and urinary estradiol concentrations. These results indicate lower estrogen availability may be associated with plant food­based diets in premenopausal women whose usual diets contain less than $25\%$ of energy as fat.

• Korean Journal of Animal Reproduction
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• v.15 no.2
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• pp.117-124
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• 1991

This stduy was conducted to find out the changes of estradiol-17$\beta$ and progesterone levels in the plasma of Cheju mares during gestatation period and before and after parturition with 12 heads of Cheju ponies. The results are as follows : 1. The estradiol-17$\beta$ and progesterone levels on the 1~4 months showed 61.6~134.2pg/ml and 7.74~9.20ng/ml respectively, but the estradiol-17$\beta$ levels rapidly increased to 426.4~1772.9pg/ml, and the progesterone levels decreased to 1.42~5.43ng/ml on the 5~10 months of gestation period. 2. The progesterone levels of the pregnant and the non-pregnant mares showed 4.80ng/ml and 0.04ng/ml in winter, respectively, but both of the two appeared 1,211.5pg/ml and 99.4pg/ml of estradiol-17$\beta$, respectively. Therefore the diagnosis of pregnancy might be more accurate with the levels of estrdiol-17$\beta$ in autumn. 3. The progesterone levels showed 3.20ng/ml the day before parturition and less than 1ng/ml on 2 days after parturition. The estradiol-17$\beta$ levels, showing the rising trend, and 90.1~162.4pg/ml up to 10 days.

• Korean Journal of Biological Psychiatry
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• v.2 no.1
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• pp.91-99
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• 1995

A on-off study was designed to evaluate the effects of addition of transdermal esrtradiol to tricyclic antidepressants on depression level, vasomotor symptom(hot flush), sexual functions and hormonal status, plasma 5-hydroxyindoleascetic acid(5-HIAA) level in postmenopausal women with depression. Plasma level of estradiol, progesterone, LH, FSH, prolactin and 5-HIAA was measured by Time-resolved fluoroimmunoassay and HPLC(High Performance Liquid Chromatography). To asses their symptoms, the BDI(Beck Depression Inventory) and modified symptom scale, extracted from women's health questionnaire were used. Depression score, sexual function score were decreased by the last 4-weeks of addition of transdermal estradiol to antidepressant treatment, not Significant, but vasomotor symptom (hot flushes) score was decreased significantly(p<0.05) by the last 4-weeks of the given treatment. Thus, during addition of transdermal estradiol to antidepressants treatment, only vasomotor symptom(hot flushes) was improved significantly, but depression level was not changed in postmenopausal women with depression. Plasma FSH, estradiol and prolactin level was not changed in postmenopausal women with depression. Plasma FSH, estradiol and prolactin levels were increased by the last 4-weeks of the treatment. There were not significant correlations between clinical symptoms and plasma hormonal status and 5-HIAA level in baseline. After the last 4-weeks of transdermal estradiol treatment, the change of depression score was correlated significantly with change of serum prolactin and 5-HIAA level and the change of vasomotor symptom score was correlated significantly with the change of plasma prolactin level.