• Clinical and Experimental Reproductive Medicine
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• v.14 no.1
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• pp.61-70
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• 1987

This study was carried out to investigate the effects of the antiestrogens, LY-117018 and tamoxifen on reproductive organ of ovariectomized immature rats and also to elucidate the mechanism of action of said compounds by bioassay. Each of LY-117018, tamoxifen and estradiol-17${\beta}$ was administered to ovariectomized immature rats at various dose levels. Forty hours after drug administration, tested rats were sacrificed and uterine wet weight, DNA and RNA contents in uterine and liver tissues were investigated. At the same time, uterine wet weight was also investigated with some other rats treated with 125${\mu}g$ of LY-117018 together with increasing doses of tamoxifen. Ovariectomized immature rats given 25${\mu}g$ single dose of each drug were sacrificed on Day 1, 2, 3, 4, and 5 after drug administration and uterine was weighed to estimate the duration of action of LY-117018 and tamoxifen. The results were summarized as follows: 1. The administration of LY-117018 or tamoxifen to ovariectomized rats increased uterine wet weight and DNA and RNA contents in uterine tissues with more increase in tamoxifen groups, but significant differences between groups treated at dose levels of 5${\beta}$ or more of both drugs were observed. Estradiol-17${\beta}$ groups showed significant increases in each group(P<0.01). 2. The administration of LY-117018 or tamoxifen to each group significantly increased DNA and RNA contents in liver tissues with more increase in tamoxifen groups. Estradiol-17${\beta}$ groups showed no significant differences between treatment groups of 5${\beta}$ or more. 3. Treatment with 125${\beta}$ of LY-117018 together with various doses of tamoxifen resulted in more increase of uterine wet weight than treatment with a single dose of LY-117018 or tamoxifen. 4. Treatment with 0.2${\beta}$ of LY-117018 or tamoxifen in ovariectomized rats decreased uterine wet weight,DNA and RNA contents in liver and uterine tissues compared with ovariectomized control. 5. The duration of effective action of LY-1l7018 and tamoxifen was 4 days or more. 6. There was significant difference(P<0.001) in uterine wet weight between Day 9after ovariectomy (two days after LY-117018 or tamoxifen treatment) and Day 10(63.7${\pm}$3.5mg, 39.2${\pm}$9.9mg, respectively).

• Biomedical Science Letters
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• v.7 no.1
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• pp.27-30
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• 2001

We have examined if lactic acid bacteria could suppress the toxic effect of bisphenol A. Lactobacillus casei YA-70 was chosen as representative. Thirty rats were divided into two groups (immature and mature) according to the weight. Each group was divided again into the control group (only alcohol treatment), bisphenol A treated group, and bisphenol A plus Lactobacillus casei YA-70 treated group. When 500 ppm of bisphenol A was fed everyday, 83% of immature group and 50% of mature group died within 3 weeks. Their internal organs, mainly livers and lungs, were changed in color and severely damaged. In the intestine of 5 ppm-fed group tumor-like nodules were observed. However, their number and size were markedly decreased when Lactobacillus casei YA-70 was supplemented in diet. This study strongly indicates that Lactobacillus casei YA-70 might play an important role to suppress the toxic effect of endocrine disruptor.

• Proceedings of the Zoological Society Korea Conference
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• 1996.04a
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• pp.43.2-43
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• 1996

No Abstract, See Full Text

• Parasites, Hosts and Diseases
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• v.31 no.2
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• pp.91-98
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• 1993

To determine the infectivlty and maturity of nletacercanae of Parqgonimur westermani after keeping at low temperature for a long period, 45 mice and 45 rats were each infected with 20 metacercariae which were kept at $4^{\circ}C$ for 8 to 234 days. The worm recovery in mice increased with age of worm and reached a peak of 32% at 41-50 days and then decreased with age. The rate In rats first decreased to a lowest point of 6% at 71-100 days and then Increased with age. In 42 infected mice and 41 infected rats, 187 immature worms (183 tiny and 4 Juvenile ones) and 190 worms (164 tiny, 19 Juvenile and 7 mature ones) were recovered respectively. Two wormcysts with eggs only and 8 empty wormcysts were also found In the rats. In addition, the frozen metacercanae can still develop to mature worms in SD rats.

• Journal of Veterinary Clinics
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• v.24 no.4
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• pp.563-567
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• 2007

This study evaluated the effect of ANTORIN R-10(pFSH), a commercially available follicle stimulating hormone on ovarian morphology, on follicular development and serum estradiol levels in rats. Immature female Wistar S/T rats(27 day old; 80-100 g B.wt) maintained under controlled environmental conditions($22{\pm}2^{\circ}C$; 50% humidity; 12 h light/12 h dark cycle) with free access to standard laboratory feed and tap water were utilized. Animals were allowed to acclimatize to the new environment for at least 2 weeks before being included in the experiment. Rats were randomly allotted to 5 groups(Control, SL 0.1AU, SH 0.2AU, TL 0.1AU and TH 0.2AU). ANTORIN R-10 was subcutaneously injected twice daily for 3 days. Twenty hours after hormone treatment, blood was collected to estimate the serum estradiol $17-\beta$ concentration. Immediately, all rats were sacrificed and the ovarian morphology, ovary weight and number of follicles were recorded. Ovaries were fixed for histomorphological examination. Higher standard and treatment groups were significantly increased on ovary weight and the number of follicles more than 1mm compared with lower standard and treatment. However, no difference revealed between standard and treatment groups. ANTORIN R-10 was similar effects of follicles development and maturation compared with House standard FSH.

• BMB Reports
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• v.32 no.4
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• pp.339-344
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• 1999

We studied the effects of ginsenosides in immature rats based upon the previous results that ginseng has a suppressive or anticonvulsive activity. To examine the suppressive effect of ginsenosides on kainic acid-induced seizures, the severities and frequencies were observed for 4 h after injection of kainic acid (KA; i.p., 2 mg/kg b.w.) using 10-day-old male Sprague-Dawley rats ($22{\pm}2\;g$). Protopanaxadiol saponins such as ginsenoside-Rb1 (Rb1), ginsenoside-Rb2 (Rb2), ginsenoside-Rc (Rc), and ginsenoside-Rd(Rd) generally reduced the seizure activities while protopanaxatriol saponins such as ginsenoside-Rg1 (Rg1) and ginsenoside-Re (Re) rather increased stereotypic "paddling-like" movements. When vinyl-GABA (v-G) was injected together with Rb1 or Rc, KA-induced seizure severities were additionally reduced only by the injection of Rc, but not by Rb1. The level of gamma isozyme of protein kinase C (PKC-${\gamma}$) in the hippocampus increased about three times as much as that of normal rats at 4 h after KA injection. The increased level of PCK-${\gamma}$ by KA was significantly reduced to about 35% by the coinjection with v-G alone, but it was not changed by v-G together with Rb1 or Rc. The increased level of PKC-${\gamma}$ at 4 h after injection of KA was not consistent with the reduction of seizure severities between Rb1 and Rc. These results suggest that Rc and Rb1 may reduce seizure severity independent of PKC-${\gamma}$ levels, and Rc may additionally act with v-G regarding the GABA metabolism during the stage of KA-induced seizures in the immature rats.

• Toxicological Research
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• v.16 no.1
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• pp.33-37
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• 2000

Hershberger assay is known as one of the in vivo-short-term scrrning assays for endocrine disrupting chemicals (EDCs), but this method is not a validated test system. In the present study, the establishment of Hershberger assay to detect EDCs was tried using a model substance, di(n-butyl)phthalate (DBP), a plasticizer for plastics. Thirty-six immature male rats were randomly assigned to six groups: DBP 0, 40, 200, and 1000mg/kg, a positive control (flutamide 20 mg/kg), and a combination group(DBP 1000mg/kg and testosterone 50 ug/kg). DBP and flutamide were administered by gavage to male rats from day 21 to 40 post partum. Testosterone was subcutaneously injected during the same period. We evaluated body weigth gain, weights of ventral prostate, seminal vesicle, and levator ani and bulvocavernous muscle, and serum concentrations of testosterone and lutenizing hormone in male rats. The weights of seminal vesicle and levator ani and bulvocavernous muscle of males receiving 1000mg/kg of DBP was significantly lower than controls. There was no effect of DBP-treatment on body weight gain, prostate weight, and hormone concentrations. In the positive control group, the weights of seminal vesicle and levator ani and bulvocavernous muscle of males receiving 20mg/kg of flutamide were significantly lower than controls. In the combination group, there was no effect of co-treatment of DBP and testosterone on all parameters effect against DBP. This method was found to be a useful short-term screening assay system for EDCs.

• Journal of Preventive Medicine and Public Health
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• v.43 no.2
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• pp.131-137
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• 2010

Objectives: Bisphenol A diglycidyl ether (BADGE) is a liquid compound obtained by condensation of two molecules of epichlorohydrin with one molecule of bisphenol A. General and reproductive toxicity with BADGE has been reported higher than 1000 mg/kg/day. This study was performed to show the effects of acute exposure to BADGE below 1000 mg/kg/day on the testis in adult male rats. Methods: BADGE was administered by gastric lavage in a single dose of 500, 750, 1000, and 2000 mg/kg/day in 8-week old male SPF Sprague-Dawley rats. The right testis was processed for light microscopic analysis. The left testis was homogenized and spermatids were counted to determine the daily sperm production and daily abnormal sperm production. The sperm count, sperm motility, and incidence of abnormal sperm were estimated in the epididymis. In testicular sections, the seminiferous tubules were observed for qualitative changes. The progression of spermatogenesis was arbitrarily classified as full-matured, maturing, and immature. The specimen slide was observed at 3 points and 10 seminiferous tubules were evaluated at each point. Results: The male rats exposed to single oral dose of BADGE at 750, 1000, and 2000 mg/kg/day were significantly increased the number of immature and maturing sperm on the testis. There were no significant differences with respect to sperm head count, sperm motility, and sperm abnormality in the BADGE treatment groups. Conclusions: These results suggest that single oral exposure of BADGE 750 mg/kg/day can affect adult male testis development.

• Environmental Mutagens and Carcinogens
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• v.20 no.1
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• pp.1-6
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• 2000

자궁내 반응에 대한 용량 의존적인 효과를 검색하기 위해 에스트로겐 agonist 및 antagonist를 사용하여 미성숙 랫드에서 uterotrophic assay를 실시하였다. 김(2000) 등은 이미 난소절제랫드를 이용한 3-day uterotrophic assay에서 에스트로겐성 물질에 대한 검색 시험을 실시한 바 있다. 양성대조물질인 17-ethinyl estradiol (EE)을 미성숙랫드에 매일 3일간 피하 투여하였으며, EE의 에스트로겐 활성을 차단하기 위한 항에스트로겐성 물질인 ZM189.154은 EE와 병행 투여하였다. 본 시험 결과 EE 1.0$\mu\textrm{g}$/kg 이상 투여군에서는 자공 비대와 fluid 저류등이 대조군에 비해 육안적으로 뚜렷하게 나타났다. 자궁무게(wet 및 blotted)는 용량 의존적으로 증가하였으며, 특히, EE 1.0$\mu\textrm{g}$/kg 이상에서는 유의성있는 증가를 나타내었다. 또한 질무게 증가도 자궁무게 증가와 일치 하였다. EE 0.3$\mu\textrm{g}$/kg을 투여한 후 ZM189, 154 0.1 mg/kg 및 1.0 mg/kg 투여와 비교할 때 EE에 의해 유도된 에스트로겐 활성이 용량 의존적으로 감소되었으나 유의성 있는 결과는 ZM189, 154 1.0 mg/kg군에서만 나타났다. 본 연구결과 EE는 uterotrophic assay에서 자궁 무게 (wet와 blotted)를 용량 의존적으로 증가시켰으며, ZM189, 154 1.0mg/kg은 EE의 에스트로겐 활성을 유의하게 감소시켰다. 따라서 미성숙 랫드를 이용한 3-day uterotrophic assay는 내분비계 장애물질 검색 시험법으로 우수하다는 것을 알 수 있었다.

• Korean Journal of Veterinary Research
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• v.26 no.1
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• pp.31-37
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• 1986

The present study has been carried out to elucidate the antiestrogenic effects of tamoxifen on RNA and protein synthesis in uteri of immature rats. Immature female Sprague-Dawley rats were allocated into 4 groups and injected with $5{\mu}g$ of estradiol-$17{\beta}$, $50{\mu}g$ of tamoxifen, a combination of both, or vehicle only subcutaneously three times with an interval of 24 hours respectively. The specific activities of $^3H$-uridine incorporation into uterine RNA and those of $^3H$-leucine incorporation into uterine protein were measured before and 1, 3, 6, 12, 24, 48 and 72 hours after the above treatments. The results obtained were summarized as follows; 1. Tamoxifen itself increased RNA synthesis an hour after treatment(169.18% of control), but it's specific activity was reduced to control level after 3 hours. Tamoxifen inhibited significantly (p<0.01) the activity of RNA synthesis of estradiol-$17{\beta}$. 2. The increasing rate of protein synthesis was lower in tamoxifen treated group than that in estradiol-$17{\beta}$ treated group. While the rate was steadily increased up to 357.4% of control by estradiol-$17{\beta}$ in 72 hours, tamoxifen itself failed to increase the rate after 24 hours and significantly (p<0.01) inhibited the activity of estradiol-$17{\beta}$(-167.4%).