• Toxicological Research
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• 제16권4호
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• pp.302-309
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• 2000

The purpose of this study is to investigate toxic effects of iso-butylalcohol (iBA) in Sprague-Dawley (SD) rats under the exposure of 6 hours a day, 5 days a week for 13 weeks by inhalation, and to evaluate the occupational safety of iBA in comparison with the permissible exposure level (PEL) stipulated by the Occupational Safety and Health Administration (OSHA). iBA did not induce any abnormal changes from the aspects of clinical signs, feed consumption, ophthalmic test, urinalysis, hematology and blood chemistry during and at the terminal of the inhalation toxicity tests. We did not find any abnormal findings in the gross and microscopic observations due to the inhalation of iBA. There was no alteration in relative organ weights by the inhalation of iBA. No observed adverse effect level (NOAEL) of iBA was considered to be more than 3,000 ppm in rats under the inhalation of 6 hours a day, 5 days a week for 13 weeks. Fifty ppm of iBA, the PEL regulated by OSHA, is too conservative for working places. As iBA showed no abnormal observations in all the experimental parameters at any concentration under this experimental condition, we suggest that 150 ppm is safe enough for the PEL of iBA in the working areas, even taking into onsideration that OSHA lowered the PEL to 50 ppm for fear of the probable risk of its skin irritation.

• Toxicological Research
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• 제27권4호
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• pp.231-240
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• 2011

Gryllus bimaculatus (Gb) was orally administered at doses of 0, 0.04, 0.2, 1 and 5 g/kg bw/day for 13 consecutive weeks. There were no observed clinical signs or deaths related to treatment in all the groups tested. Therefore, the approximate lethal oral dose of G. bimaculatus was considered to be higher than 5 g/kg in rats. Throughout the administration period, no significant changes in diet consumption, ophthalmologic findings, organ weight, clinical pathology (hematology, clinical chemistry, coagulation, and urinalysis) or gross pathology were detected. Minor changes were found in hematological parameters for the 5 g/kg Gb-treated group (triglyceride reduction of 35.8%), but all changes were within normal physiological ranges. Microscopic examination did not identify any treatment-related histopathologic changes in the organs of Gb-treated rats in the high dose group. From these results, one can conclude that the no-observed adverse effect level (NOAEL) of G. bimaculatus is higher than 5 g/kg bw/day in rats.

• Toxicological Research
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• 제33권2호
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• pp.165-171
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• 2017

Bisphenol A (BPA) is a monomer used in a polymerization reaction in the production of polycarbonate plastics. It has been used in many consumer products, including plastics, polyvinyl chloride, food packaging, dental sealants, and thermal receipts. However, there is little information available on the inhalation toxicity of BPA. Therefore, the aim of this study was to determine its inhalation toxicity and effects on the estrous cycle, spatial learning, and memory. Sprague-Dawley rats were exposed to 0, 10, 30, and $90mg/m^3$ BPA, 6 hr/day, 5 days/week for 8 weeks via whole-body inhalation. Mortality, clinical signs, body weight, hematology, serum chemistry, estrous cycle parameters, performance in the Morris water maze test, and organ weights, as well as gross and histopathological findings, were compared between the control and BPA exposure groups. Statistically significant changes were observed in serum chemistry and organ weights upon exposure to BPA. However, there was no BPA-related toxic effect on the body weight, food consumption, hematology, serum chemistry, organ weights, estrous cycle, performance in the Morris water maze test, or gross or histopathological lesions in any male or female rats in the BPA exposure groups. In conclusion, the results of this study suggested that the no observable adverse effect level (NOAEL) for BPA in rats is above $90mg/m^3$/6 hr/day, 5 days/week upon 8-week exposure. Furthermore, BPA did not affect the estrous cycle, spatial learning, or memory in rats.

• Biomolecules & Therapeutics
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• 제11권1호
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• pp.72-79
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• 2003

The present study was conducted to investigate the potential subacute toxicity of AS6, [(3$\beta$, 4$\alpha$)-3,23-dihydroxyurs-12-en-28-oic acid], by a 4-week repeated oral administration in Sprague-Dawley rats. To test the subacute toxicity, AS6 was administered once daily by gavage to rats at dose levels of 0, 250, 500, and 1000 mg/kg/day for 4 weeks. There were no treatment-related effects on mortality, clinical signs, body weight, food and water consumption, ophthalmoscopy, urinalysis, hematology, serum biochemistry, necropsy findings, organ weights, and histopathology in any treatment group. In the condition of this study, target organ was not observed and the no-observed-adverse-effect level (NOAEL) was considered to be 1000 mg/kg/day for both male and female rats.

• Toxicological Research
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• 제18권2호
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• pp.139-147
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• 2002

Hantaan (HTNV) and Puumala (PUUV) viruses cause hemorrhagic fever with renal syndrome in human. In the present study, the repeated dose toxicity of the HTNV-PUUV combination vaccine was evaluated in Sprague-Dawley rats. Animals were injected subcutaneously for 28 days with dosages of 0, 0.017, 0.17 and 1.7 dose/kg body weight per day, respectively. No any significant changes of body weight, food and water consumptions were shown. There were no death and clinical findings during the experimental period. In both male and female rats, there were not significant changes in hematological and serum biochemical analysis, urinalysis, and ophthalmoscopic and histopathological examination. These results indicate that the HTNV-PUUV combination vaccine may have no toxic effects and no observed adverse effect level (NOAEL) may be over 1.7 dose/kg/day at subcutaneous route in rats.

• 대한수의학회지
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• 제54권1호
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• pp.31-38
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• 2014

Cordyceps is a fungus used as a traditional medicine in China, Japan, and Korea. Paecilomyces (P.) japonica is a new cordyceps that was recently cultivated on silkworm pupae in Korea. The present study evaluated the toxicological effects of P. japonica in rats. Forty rats were treated with oral doses of P. japonica (0, 20, 100, or 500 mg/kg/day) for 4 weeks. Twenty additional rats were treated with 0 or 500 mg/kg/day of P. japonica for 4 weeks and then maintained for 2 weeks without treatment. Clinical signs, body weight, food and water consumption, and organ weight as well as hematology, serum biochemistry, and histopathology data were examined. Body weight gain of the group treated with 500 mg/kg/day was significantly reduced. Microscopically, karyomegaly, single cell necrosis, and mitosis were observed in the renal tubular epithelium of all treated groups. In conclusion, P. japonica caused a reduction of body weight and renal injury in rats. The no observed adverse effect level (NOAEL) of P. japonica was less than 20 mg/kg/day.

• Toxicological Research
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• 제17권
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• pp.41-45
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• 2001

The methods used for risk assessment from exposure to chemicals are well established. in most cases where toxicity other than carcinogenesis is being considered, the standard method relies on establishing the No Observed Adverse Effect Level (NOAEL) in the most sensitive animal toxicity study and using an appropriate safety factor (SF) to determine the exposure which would be associated with an acceptable risk. For carcinogens a different approach is used because it has been argued there is no threshold of effect. Thus mathematical equations are used to extrapolate from the high doses used in ani-mal experiments. These methods have been strongly criticised in recent years on several grounds. The most cogent criticisms are a) the equations are not based on a thorough understanding of the mechanisms of carcinogenesis and b) the outcome of a risk assessment based on such models varies more as a consequence of changes to the assumptions and equation used than it does from the data derived from carcinogenicity experiments. Other criticisms include the absence of any measure of the variance on the risk assessment and the selection of default values that are very conservative. Recent advances in the application of risk assessment emphasise that measures of both the exposure and the hazard should be considered as a distribution of values. The outcome of such a risk assessment provides an estimate of the distribution of the risks.

• Biomolecules & Therapeutics
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• 제12권1호
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• pp.49-54
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• 2004

The present study was conducted to investigate the potential subacute toxicity of CKD-602 by a 5-day repeated intravenous administration in Sprague-Dawley rats. CKD-602 was administered intravenously to male rats at dose levels of 0, 0.08, 0.2, and 0.5 mg/kg for 5 days. Studies included general observation, body weight changes, ophthalmoscopic examination, hematology, se겨m biochemistry, gross findings at necropsy and organ weight measurement. There were no deaths in any treatment group and treatment related clinical sign was depilation in the 0.5 mg/kg groups. The decrease or suppression of body weight was also observed dose-dependently in all treatment groups. Decreased leukocyte in all treatment groups, decreased platelet in the above 0.2 mg/kg groups and increase in the serum levels of total cholesterol in the 0.5 mg/kg group were considered as a treatment related toxic effects. Decreased weight of thymus in all treatment groups anti decreased weight of spleen in the above 0.2 mg/kg group were observed. The intravenous administration of CKD-602 caused depilation and decreased weight and had toxic effect on the leukocyte, platelet, spleen and thymus. In the condition of this study, the target organs were spleen and thymus and the toxic effect level was determined to be 0.2 mg/kg, but no-observed-adverse-effect level (NOAEL) was considered to be lower than 0.08 mg/kg.

• 한국산업보건학회지
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• 제24권2호
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• pp.169-181
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• 2014

Objectives: The purpose of this study was to obtain information regarding classification and health hazards that may result from a 13-week inhalation exposure to 2-methylpentane by Sprague-Dawley rats. Materials: The testing method was conducted in accordance with OECD guidelines for the testing of chemicals No. 413. The rats were divided into four groups(ten male and ten female rats in each group) and exposed to 0 ppm, 290 ppm, 1,160 ppm, 4,640 ppm 2-Methylpentane in each exposure chamber for six hours per day, five days per week, for 13 weeks. Results: No death or particular clinical presentation including weight change and change of feed rate was observed. The relationships between dose, gender and response were also not significantly changed in urinalysis, hematologic examination, or biochemical examination of blood(except for total cholesterol being up, total protein being up, and chloride ion being down in males), and blood coagulation time. For the relative weight measurement of organs, in the male group the weight change of both kidney and liver were increased in proportion to dose. In histopathological examination, nephropathy in the kidney(cystic change of renal tubules, regenerative tubule, inflammatory cell infiltration and necrosis in the interstitial tissue) was increased in a dose-dependent manner in the male group(290 ppm, 1,160 ppm, 4,640 ppm). However, other organs were not affected by the test substance. Conclusions: 2-methylpentane was estimated as a chemical causing nephropathy in the male group. NOAEL(No Observable Adverse Effect Level) in the female group is more than 4,640 ppm, while inthe male group it is less than 290 ppm.

• 대한약침학회지
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• 제17권2호
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• pp.73-79
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• 2014

Objectives: This study was performed to analyze a 13-week repeated dose toxicity test of Sweet Bee Venom (SBV) extracted from bee venom and administered in Sprague-Dawley (SD) rats. Methods: Male and female 5-week-old SD rats were treated once daily with SBV (high-dosage group: 0.28 mg/kg; medium-dosage group: 0.14 mg/kg; or low-dosage group: 0.07 mg/kg) for 13 weeks. Normal saline was administered to the control group in a similar manner (0.2 mL/kg). We conducted clinical observations, body weight measurements, ophthalmic examinations, urinalyses, hematology and biochemistry tests, and histological observations using hematoxylin and eosin (H&E) staining to identify any abnormalities caused by the SBV treatment. Results: During this study, no mortality was observed in any of the experimental groups. Hyperemia and a movement disorder were observed around the area of in all groups that received SBV treatment, with a higher occurrence in rats treated with a higher dosage. Male rats receiving in the high-dosage group showed a significant decrease in weight during the treatment period. Compared to the control group, no significant changes in the ophthalmic parameters, the urine analyses, the complete blood cell count (CBC), and the biochemistry in the groups treated with SBV. Compared to the control group, some changes in organ weights were observed in the medium-and the high-dosage groups, but the low-dosage group showed no significant changes. Histological examination of thigh muscle indicated cell infiltration, inflammation, degeneration, and necrosis of muscle fiber, as well as fibrosis, in both the medium- and the high-dosage groups. Fatty liver change was observed in the periportal area of rats receiving medium and high dosages of SBV. No other organ abnormalities were observed. Conclusion: Our findings suggest that the No Observed Adverse Effect Level (NOAEL) of SBV is approximately 0.07 mg/kg in male and female SD rats.