• Korean Journal of Veterinary Research
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• v.32 no.2
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• pp.245-250
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• 1992

This study was performed to demonstrate the presence of large granular lymphocyte(LGL) in Sprague-Dawley(SD) rats and morphologically observe NK cell and also establish the method of isolation of natural killer cell in SD rats. By percoll discontinuous density gradients centrifugation, highly enriched LGL population were shown to fraction 2(border line between 44.2% and 50.8%). LGL were shown to bind selectively to YAC1 mouse lymphoma cell. This fraction expressed very high NK cell cytolysis. Therefore, we thought that LGL have NK activity in SD rats. The Morphology of rat LGL is very similar to that of human LGL. These cells have an eccentric kidney-shaped nucleus. Their most distinctive feature was their cytoplasmic azurophilic granules. Another distinguishing feature of rat LGL was their high cytoplasmic : nuclear ratio. It was concluded that LGL played a role part in mediating natural killer activity in this species.

• Toxicological Research
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• v.18 no.4
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• pp.397-400
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• 2002

This study was carried out to investigate the acute toxicity of G. bimaculatus in Sprague-Dawley rats. G. bimaculatus was administered orally at doses of 8, 40, 200, 1000 and 5000 mg/kg. in this study, number of deaths, clinical sign, body weights, and pathological examination were investigated for 14 days after administration of G. bimaculatus. The results indicate that G. bimaculatus did not show any toxic effect in rats and oral $LD_{50}$ value was over 5000 mg/kg in Sprague-Dawley rats.

• Korean Journal of Veterinary Pathology
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• v.2 no.1
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• pp.47-52
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• 1998

The incidence of spontaneous testicular atrophy and its morphological changes during stage-specific spermatogenesis were investigated in male Sprague-Dawley rats at 10, 19, and 32 weeks of age. The incidence of testicular atrophy was 0.2%(2/90) 7.9%(9/114) and 10%(4/40) in 4, 13 and 26 weeks respectively. The epididymis with testicular atrophy had low sperm density. In the minimally affected tests scattered tubules showed complete depletion of germ cells without stage specificity. Testes with moderate to severe testicular atrophy showed seminiferous tubules lined with dense Sertoli cell population. While Leydig cells in the interstitium appeared hypertrophy they were immunohistochemically negative for proliferating cell nuclear antigen a marker of cell proliferation.

• Journal of Life Science
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• v.11 no.2
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• pp.97-102
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• 2001

This study was performed to evaluate the actue sbucutaneous toxicity of hydroxyapatite sinter produced from tuna bone in Sprague-Dawley(SD) rats. Hydroxyapatite sinter was administrated at dose levels of 5000, 2500, 1250, 625, 312.5 and 0 mg/kg. After single subcutaneous adiminstration to both sexes to both sexes SD rats, we observed rats for 14 days. Hydroxyapatite sinter did not induce any toxic signs inmortalities, clinical findings, body weights and gross findings of the rats. In view of result, it was impossible to estimate LD/ sub 50/ values in SD rats. In conclusion, these results suggest that hydroxyapatite sinter produced from tuna bone has no effect on acute subcutaneous toxicity in SD rats.

• Journal of the Korean Society of Food Culture
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• v.34 no.6
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• pp.801-809
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• 2019

Abeliophyllum distichum Nakai is a deciduous shrub of a flowering plant in Oleaceae. It is an important plant resource and consists of only one species in the entire world. A. distichum Nakai is well known an edible, medicinal herb in its habitat districts, but the toxicological evaluation for the safe use of its extract is still insufficient. The study characterized the toxicity of an Abeliophyllum distichum Nakai ethanol extract in Sprague-Dawley (SD) rats and determined the safe dosage levels in a 13 weeks toxicity study. Abeliophyllum distichum Nakai ethanol extract was orally administered once daily for 2 weeks at 0, 500, 1,000 and 2,000 mg/kg/day to male and female SD rats. while recording the clinical signs of toxicity, body weight, food intake/consumption, eye test and urine analysis. Only the total protein frequency in the urine of male SD rats (p<0.05), the right ovary of the 500 mg/kg group (p<0.01) and the right adrenal gland of the 1,000 mg/kg group (p<0.05) in the female rats showed statistically significant changes. But no toxic effects were noted from repeated-dose administration of the Abeliophyllum distichum Nakai ethanol extract in the SD rats during the observation period. The post-mortem examinations showed no test substance-mediated changes. The hematological analysis and clinical blood chemistry data demonstrated no toxic effects from repeated-dose administration of Abeliophyllum distichum Nakai ethanol extract in the SD rats during the observation period. Based on these results, this data suggests that a dose of 1,000 mg/kg/day is a highest treatment to administer when conducting a further 13 weeks toxicity study.

• Toxicological Research
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• v.12 no.2
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• pp.309-318
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• 1996

This study was conducted to investigate the subacute intravenous toxicity of rHu-EPO in Sprague-Dawley rats. rHu-EPO was daily administered to male and female rats for 30 days with different dose levels(100, 500, 2,500 unit/ kg). After the administration period of 30 days, 5 males and 5females rats per each dose group were assigned for recovery period of additional 30 days. There were no clinical signs compared with control group but slight decrease in spontaneous motor activities and locomotions were observed at high dose groups of males and females. In males, feed consumption was reduced at 500 unit/kg and body weight gain was retarded. In the administration sites of tail, focal congestion was observed in a few animals treated with rHu-EPO. No deaths were occurred during the course of study. In hematological examination. a significant increase of hemoglobin and hematocrit was observed in the males and females rats receiving high dose of rHu-EPO. rHu-EPO administration for 30 days showed a marked decrease in glucose concentration. At the highest dose groups, there was a significant incerase in the weights of spleens in both sexes. but this was considered to be related to its pharmacological activity. These results indicate that rHu-EPO does not induce any significant toxic effect on Sprague-Dawley rats for 30 days.

• YAKHAK HOEJI
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• v.43 no.3
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• pp.358-368
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• 1999

Subacute toxicity study was performed in Sprague-Dawley rats after daily dermal administration of Sangmosu (0.2, 1.0 and 5.0 g/kg) for one month. There were no clinical signs and pathological changes compared with control group. Bodyweights were not significantly changed between control and Sangmosu treatment groups. In histopathological examinations, there were some pneumonia in lung tissues at all groups of Sangmosu treatment including control, but it was not considered to be caused by Sangmosu. These results suggest that Sangmosu does not induce any significant subacute dermal toxicities in Sprague-Dawley rats.

• Toxicological Research
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• v.18 no.2
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• pp.167-174
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• 2002

Historical control data have been shown to be valuable in the proper interpretation and validation of reproductive toxicology studies. The present data were compiled from rat fertility and early embryonic development studies conducted at Korea Institute of Toxicology during the 1994∼2001 period. These data were assembled in order to provide background information for the general and reproductive data collected in 11 fertility and early embryonic development studies using Sprague-Dawley rats obtain-ing from the Breeding Facility, Korea Institute of Toxicology, Korea. A total of 274 males and 274 females were used in these studies during the eight-year period. Parameters of fertility and early embryonic development included clinical sign, body weights, food consumption, organ weights, estrus cycle, copulation index, precoital time, fertility index, pregnancy index, sperm parameters, and early embryonic development parameters. Most of the values were comparable to the previous historical control data reported by other investigators. These data can be wed not only as a historical data base for the meaningful interpretation of data from reproductive and developmental toxicity studies, but also as a contribution to biological characterization of Sprague-Dawley rats.

• Korean Journal of Veterinary Research
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• v.35 no.2
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• pp.375-381
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• 1995

Two intraocular tumors were identified in low and medium dosed groups of a carcinogenicity study using 200 males and 200 females Sprague-Dawley rats in Screening & Toxicology Research Center, Korea Research Institute of Chemical Technology. The tumors were grossly observed as white or yellow, unilateral nodules. They were approximately $1-2{\times}3-5mm$ in size. The tumors located in the region of iris and/or ciliary body invaded peripheral cornea. The microscopic features were usually composed of spindle cells arranged in parallel, forming gently curving bundles or whorls. The spindle cells had poorly defined cell boundaries, scant to moderate cytoplasm, fusiform nuclei and indistinct nucleoli. Mitotic figures were rare and areas of necrosis were present. The spindle cells had positive immunoreactivity for S-100 protein and vimentin but negative for desmin, collagen and HMB-45 antibody. In special histochemical studies, the spindle cells react with Gomori's stain for argyrophih fibers, Prussian blue stain for iron but negative with Masson-Fontana's stain for melanin granules. Ultrastructurally, cytoplasmic premelanosomes were not observed in the tumor cells due to the poor preservation of tumor masses. Based on the results, the tumors were diagnosed as amelanotic melanoma.

• Korean Journal of Veterinary Pathology
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• v.5 no.2
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• pp.39-42
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• 2001

A reference range data base containing organ weight values on animals used in 4 week and 13 week toxicity tests is described. Data listed include the values of minimum, maximum, mean and standard deviation for each of the following organ weights. Organs: Brain, heart, liver, spleen, kidney, adrenal gland, testis, ovary. This study was undertaken to determine organ weight reference values of Ktc: SD rats