• 한국수의병리학회:학술대회논문집
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• 한국수의병리학회 2002년도 추계학술대회초록집
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• pp.149-149
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• 2002

Epidemiologically the incidence of liver cancer is markedly sex-differentiated, with a much higher frequency in men than in women. In experimental animals, it is also higher in male than in female irrespective of carcinogen-induced or spontaneous tumors. Therefore, we tried to investigate the modulating effects of sex hormones in experimental hepatocarcinogenesis. For induction of liver tumors, mini-osmotic pump containing diethylnitrosamine at a dose level of 47.5mg was implanted into the peritoneal cavity of the rat at 6 weeks old. To remove the effects of male sex hormones, the animals of group 2 were castrated one week prior to DEN treatment. To see the effects of estrogen, pellet containing 1g or 10g of estradiol-3-benzoate was infused subcutaneously to the animals of group 3 and 4 one week prior to DEN treatment. The pellets were exchanged every 4 weeks until sacrifice. All animals were sacrificed at 26 weeks after DEN treatment. The tumor incidences in group 1 (DEN alone), group 2 (DEN +castration), group 3(DEN +EB 1g) and group 4 (DEN +EB 10g) were 100％ (15/15), 93.3％ (14/15), 85.7％ (12/14) and 66.7％ (10/15), respectively, showing that the value of group 4 is significantly different from that of group 1. Tumor multiplicity data of group 1, 2, 3 and 4 were 5.470.73, 2.800.51, 2.070.41 and 1.670.46, respectively, showing castration or EB treatment reduced number of liver tumors significantly (P<0.001). With immunohistochemistry and Western blotting of ER the expressions were detected in normal adjacent liver cells but decreased or lost in tumor cells. From these results we conclude that female sex hormone, especially estrogen, may act as a liver tumor suppressor, and it seemed that the down regulation of ER may be associated with liver tumor development.

• Journal of Korean Biological Nursing Science
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• 제10권1호
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• pp.80-87
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• 2008

Purpose: Hypoestrogenism caused by ovariectomy, disease, or menopause is associated with increased obesity in women. Altered fat distribution and weight gain are consequences of menopausal hypoestrogenism, but the mechanisms responsible are not completely known. This study examined the effect of estrogen on obesity in ovariectomized rats. Method: The groups of female rats were 4 weeks post ovariectomy (OVX) or, 4 weeks post-sham operation (SHAM), and 2 weeks post ovariectomy followed by 2 weeks replacement with estradiol benzoate (ER-$16{\mu}g$/kg, subq, qd). Serum ghrelin level was measured by radioimmunoassay (RIA). The expression of adrenergic receptors in adipose tissue was measured by Western blotting assay. Result: OVX significantly increased body weight, serum cholesterol. Two weeks estrogen replacement reduced body weight accompanied by the increment of serum ghrelin and the reduction of the receptor ratio of adrenergic ${\alpha}_{2A}/{\beta}_1$, and ${\alpha}_{2A}/{\beta}_3$. Conclusion: We provide evidence that estrogen reduces obesity through the altered receptor ratio of adrenergic ${\alpha}_{2A}/{\beta}_1$, and ${\alpha}_{2A}/{\beta}_3$ in adipose tissue in ovariectomized rats.

• Nutrition Research and Practice
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• 제8권3호
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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.

• 한국환경보건학회지
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• 제33권5호
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• pp.379-385
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• 2007

This study was aimed to investigate the estrogenic activity of Di-(2-ethylhexyl) adipate (DEHA) using immatured type uterotrophic assay. SD rats were treated with DEHA (40, 200, 1000mg/kg/day), estradiol-3-benzoate (EB) $(1{\mu}g/kg/day)$ as positive control on the assay. In immatured-type uterotrophic assay, relative organ weights of kidney and reproductive organs such as ovary at high-dose group were significantly increased compared to those of vehicle control group. DEHA did not influence the levels of serum FSH and LH, and uterine morphological changes such as luminal epithelial height, myometrial thickness and numbers of uterine gland, and BrdU indices. In these results, there was no significant variation by DEHA treatment, suggesting that DEHA appears not to be a endocrine disrupter with estrogenic activity.

• 한국수정란이식학회지
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• 제6권2호
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• pp.37-46
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• 1991

A field trial was performed to evaluate the effects of hormone treatment on estrus induction, ovulation, embryo transfer and reproductive performance in post-weaning sows. This trial involved 61 mixed breed sows of varying parity on a commercial pig farm. Sows were allocated to one of five trials: control group involved 25 sows that were treated with a single intramuscular injection of 5 ml physiological saline, 6 sows received 1,500 IU PMSG on the day of weanning and 500 IU HCG at the onset of estrus in trial I, 7 sows received 750 IU PMSG on the day of weanning and 500 IU HCG at the onset of estrus in trial II, 5 sows were treated with the same as trial II on day 28 after weanning in trial III. and 18 sows were treated with 10 mg PGF$_2$$\alpha$ plus 2 mg estradiol benzoate on day 31 after weanning in trial IV. Ovarian responses were checked by laparotomy and ova were recovered by oviducal flushing between 40 and l00hrs after mating. Fertilized ova were transferred into the oviduts of recipient sows synchroni- zed. The results obtained were summarized as follows: 1. Percentages of sows detected in standing estrus following treatment were 86~100% among trial groups. The interval from treatment to standing estrus(6l.7$\pm$0.5lhrs) in lOmg PGF$_2$$\alpha$ and 2mg estradial henzoate treated group was significantly earlier than in other trial groups(P<0.05). 2. Average number of ovulations was 11.5~37.8 among trial groups. The ovulation rate in 1,500 IU PMSG and 500 IU RCG treated group (37.8$\pm$ 19.87) was significantly different from other trial groups(P<0.05). 3. Ova were recovered by oviducal flushing between 40~ l00hrs after mating and recovery rates of ova wore 91.4% between 40~59hrs. 4. Fertilized ova were transferred into the oviducts of 8 recipient sows synchronized with 7 to 17 ova per animal. Three of the recipients were pregnant and delivered 25 piglets. 5. Four of the donor sows in those embryo collection was not successful were pregnant following oviducal flushing and delivered 23 piglets. 6. Recurrence of estrus and farrowing performance of experimental sows were observed following the experiment was no difference among trial groups, respectively.

• 한국임상수의학회지
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• 제37권5호
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• pp.235-241
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• 2020

We aimed to determine the effect of timed artificial insemination (TAI) protocols on the pregnancy rate per insemination and pregnancy loss compared with AI performed at detected estrus in dairy cows and Korean Hanwoo cattle under heat stress. In dairy cattle, 1,250 sets of data that underwent AI during heat stress (temperature-humidity index ≥ 72) were categorized according to their TAI protocols or as controls: 1) PGF_2α-36 h-estradiol benzoate (EB)-36 h-TAI (PG-EB group, n = 113); 2) GnRH-7 days-PGF_2α-56 h-GnRH-16 h-TAI (Ovsynch group, n = 455); or 3) GnRH-6 days-Ovsynch (G6G group, n = 136). The remaining cows underwent AI at detected estrus (AIDE group, n = 546). The probability of pregnancy per AI 45 days after AI was higher (P < 0.01) in the PG-EB (odds ratio [OR]: 1.68), Ovsynch (OR: 1.48), and G6G (OR: 1.79) groups than in the AIDE group. However, the prevalence of pregnancy loss between 30 and 45 days after AI did not differ among the groups. In Hanwoo cattle, 617 sets of data inseminated artificially under heat stress were categorized into AIDE (n = 281), PG-EB (n = 194), and combined Ovsynch or G6G (n = 142) groups. The probability of pregnancy per AI 45 days after AI and the prevalence of pregnancy loss between 30 and 45 days after AI did not differ among the groups. Thus, implementation of a TAI protocol (PG-EB, Ovsynch, or G6G) in dairy cows under heat stress improves the pregnancy rate per AI versus AIDE, whereas there is no beneficial effect of TAI on the pregnancy rate of Hanwoo cattle under heat stress.

• 대한수의학회지
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• 제46권1호
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• pp.35-41
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• 2006

Vitellogenin (Vtg), a phospholipoglycoprotein precursor of egg yolk is synthesized and secreted from the liver in response to estrogens in female fish. Vtg is normally undetectable in the blood of male fish, but can be induced by exposure to chemicals possessing estrogenic activity. Thus, the presence of Vtg in blood of male fish can serve as a useful biomarker for assessing previous exposure to estrogenic compounds. In the present study, Vtg was abnormally expressed in Rhynchocypris oxycephalus using estradiol benzoate ($E_2$). As the result, it was found that the level of Vtg in blood from R. oxycephalus was increased by treated quantity of $E_2$ with dose-effect manner. Monoclonal antibodies were generated against Vtg of R. oxycephalus. The hybridoma were screened with an enzyme immunoassay for the production of specific anti-Vtg antibodies. Five positive cell lines with a high specificity were selected. Monoclonal antibodies against vtg of R. oxycephalus that was developed in this study, may be a useful bio-indicator for the detection of estrogenic contamination in the aquatic ecosystem.

• Nutrition Research and Practice
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• 제9권5호
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• pp.459-465
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• 2015

BACKGROUND/OBJECFTIVES: The effect of St. John's Wort extract (SJW) on MG-63 cell proliferation and trabecular bone loss induced by ovariectomy was examined. MATERIALS/METHODS: Proliferation, expression of estrogen receptor (ER) ${\alpha}$ and ER ${\beta}$, and gene expressions of osteoprotegerin (OPG), osteocalcin (OC) and alkaline phosphatase (ALP) were examined in MG-63 cells treated with or without SJW. Ovariectomized rats were treated with SJW at the dose of 100 or 200 mg/kg/day, ${\beta}$-estradiol-3-benzoate (E2), or vehicle only (OVX-C), and sham operated rats were treated with vehicle only (Sham-C). Serum ALP and C-telopeptide (CTX), and femoral trabecular bone loss were examined. RESULTS: SJW increased MG-63 cell proliferation and expression of ER ${\alpha}$ and ER ${\beta}$, and positive effect was shown on gene expressions of ALP, OC and OPG. SJW also showed estrogen like effect on bone associated with slowing down in trabecular bone loss. Histopathology by H&E showed rats treated with SJW displayed denser structure in metaphyseal region of distal femur compared with rats in OVX-C. SJW was shown to reduce serum CTX in OVX rats. CONCLUSION: The present study provides new insight in preventing estrogen deficiency induced bone loss of SJW and possibility for its application in bone health supplement.

• 한국수정란이식학회지
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• 제27권3호
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• pp.127-131
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• 2012

발정주기와 상관없이 CIDR을 삽입하는 날에 50 mg progesterone, 2.5 mg estradiol benzoate를 근육주사하였다. CIDR 삽입 후 4, 5일에 28 AU FSH (Antorin R10)을 4일 동안 감량법으로 주사하였다. 6, 7회 FSH 주사 후 25 mg, 15 mg $PGF_2{\alpha}$를 각각 주사한 다음, CIDR는 7회 FSH 주사 후 제거하였다. 1회째 $PGF_2{\alpha}$ 주사 후 48시간에 $200{\mu}g$ GnRH를 주사하였다. 공란우는 발정확인 후 12시간 간격으로 3회 인공수정을 실시하였으며, 수정란의 채란은 발정확인 후 7일째 회수하였다. 과배란 처리된 공란우에서 회수된 총 난자수, 이식가능 수정란, 퇴행란 및 미수정란은 각각 $11.6{\pm}7.9$, $5.5{\pm}4.4$, $3.0{\pm}3.3$ 및 $2.6{\pm}4.1$개였다. 1~2산의 공란우($8.9{\pm}1.9$)보다 3~5산의 공란우($14.3{\pm}1.3$)에서 총 난자수가 유의적으로 많았다(P<0.05). 회수된 정상 수정란 수도 3~5산의 공란우($7.3{\pm}0.8$)에서 6산 이상의 공란우($3.7{\pm}1.5$)보다 유의적으로 많았다(P<0.05). 회수된 총 난자수와 정상수정란도 각각 가을($10.1{\pm}1.8$, $4.5{\pm}1.1$)과 겨울($6.3{\pm}1.8$, $3.3{\pm}1.1$)보다 여름($16.4{\pm}2.3$, $8.1{\pm}1.4$)에 유의적으로 많았다(P<0.05). 이식가능 수정란은 겨울($3.0{\pm}1.0$)보다 여름($7.6{\pm}1.3$)에서 유의적으로 많이 회수하였다(P<0.05). 결론적으로 공란우의 산차, 과배란 처리계절은 한우수정란 생산에 영향을 미치는 것으로 나타났다.

• Journal of Animal Science and Technology
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• 제46권4호
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• pp.585-592
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• 2004

돼지에 있어서 약 115일간의 임신 기간 중 마지막 40일 동안에 유선 내에서 유액도관(duct), 분비소엽(lobules), 분비낭포(alveoli) 등의 parenchyma 조직이 현저하게 발달하게 되는데, 이는 단백질 호르몬 relaxin과 estrogen의 공동작용에 기인하여 촉진되는 것으로 알려져 있다. 최근에는 면역조직화학적 실험방법을 통해 relaxin hormone이 유선조직 세포(mammary gland parenchyma cells)에 직접적으로 작용하여 lobuloalveolar의 발달을 촉진할 수 있는 가능성을 시사하였다. 즉 Relaxin에 특이적이고 포화 가능한 Relaxin의 결합부위가 lobulo-llveolar 구조 및 유액도관(lactiferous duct)의 상피세포(epithelial cells)뿐만 아니라 혈관세포에서도 존재함을 관찰하였다. 본 연구의 목적은 유선조직 세포에 존재하는 relaxin 결합부위가 기능적으로 활성을 지닌 relaxin 수용체(functional relaxin receptor)인지를 규명하고 동시에 relaxin hormone이 유선조직 세포에 직접적으로 작용하여 lobulo-alveolar의 발달을 촉진하는 지에 대한 직접적인 증거를 제공하는 데 있다. 정상적인 생리주기를 가진 3마리의 생후 7개월 된 잡종재지에 대하여 양쪽 난소를 모두 제거하는 양측난소 절제시술(Bilateral ovariectomy)을 실시하였다.(day 0). 난소 절제시술 후 15일부터(day 15) 29일(day 29)까지 각 개체별로 estradiol benzoate(1 mg/2 ml /Com oil)를 12시간 간격으로 근육주사 하였다. 시술 후 22일째부터(day 22) 순수 정제된 relaxin을 miniature osmotic pump를 통하여 몸의 anterior end로부터 왼쪽부위의 4번째 유선에 일정한 속도(1 ug/hr)로 주입하기 시작하였으며, 동일한 개체의 오른쪽 부위의 4번째 유선에는 동일한 방업으로 생리적 식염수(대조군)을 주입하였다. 난소 절제수술 후 29일째(day 29) 각 개체를 희생하여 젖꼭지의 base로부터 1cm 떨어진 지점에서 osmotic pump의 위치로부터 가까운 parenchyma 조직 시료를 채취하여 약 5-mm cube으로 자른 다음 조직학적 분석을 위한 일반적 조직시료 처리과정을 시행하였다. 조직절편을 Weigert's iron hematoxylin과 함께 염색한 다음 Olympus AH-2 광학현미경을 이용하여 lobulo-alveolar의 발달과 세포외간 섬유사인 collagen의 밀도와 정렬정도를 조사하였다. 생리식염수로 처리된 유선조직에 있어서는 lobulo-alveolar의 발달이 거의 일어나지 못한 반면, relaxin을 처리한 유선조직은 lobulo-alveolar의 현저한 발달을 보였을 뿐만 아니라 분비낭포(alveoli) 내에서는 두드러진 분비물이 존재하였다. 또한 식염수로 처리된 유선조직에서는 비교적 조밀하고 매우 잘 발달된 collagen 섬유사 묶음을 가진 세포의 간 기질의 특징을 보였으나, relaxin 호르몬이 처리된 유선조직에서는 collagen 섬유사가 비교적 분산되어 있고 느슨하며 덜 조밀한 구조적 특징을 나타내었다. 결론적으로, 본 연구의 결과는 유선조직 내의 특이적 relaxin 결합세포가 기능적으로 활성을 지닌 relaxin 수용체를 함유하고 있으며, relaxin hormone이 유선조직 세포에 직접적으로 작용함으로써 lobulo-alveolar의 발달을 촉진함을 보여준다.