• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.17 no.3
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• pp.181-191
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• 2007

With the 2-Butanethiol, which is an unidentified inhalation toxic material, acute inhalation toxicity was tested with SD rats. The $LC_{50}$ was evaluated to be 2,500 ppm (9.22 mg/L) or higher which falls under the criteria of acute toxicity Category 3 (500<$LC_{50}$<2,500 ppm) in the Industrial Safety and Health Act. In the subchronical inhalation toxicity test by 0, 25, 100, and 400 ppm, 6 hours a day, 5 days a week, for 13 weeks repeated exposure, though no death or particular clinical presentation was observed, in the female 25 and 400 ppm group, including weight change, and in each concentration group including 400 ppm, change of feed rate, eye stimulation, motility change in male group, and lesions in blood and blood biochemical were observed. In the internal organs weight, 25, 100, and 400 ppm groups in male and 400 ppm group in female showed significant (p<0.05) changes in kidney, liver, thymus, and lung. In the pathological tissue test, severe cortical tubular hyaline droplets were observed in the male 400 ppm group, and all male rats of 400 ppm group and 2 female individuals showed tubular degeneration/regeneration accompanied with pigmentation, showing that the target organs of inhalation exposure of 2-Butanethiol are spleen, kidney, nasal cavity, and adrenal. Through the tests, the NOEL of 2-Butanethiol was evaluated to be 25 ppm (0.092 mg/L) or less for both male and female.

• Toxicological Research
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• v.33 no.4
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• pp.333-342
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• 2017

Ethyl formate, a volatile solvent, has insecticidal and fungicidal properties and is suggested as a potential fumigant for stored crop and fruit. Its primary contact route is through the respiratory tract; however, reliable repeated toxicological studies focusing on the inhalation route have not been published to date. Therefore, the present study was conducted to investigate the safety of a 90-day repeated inhalation exposure in rats. Forty male and 40 female rats were exposed to ethyl formate vapor via inhalation at concentrations of 0, 66, 330, and 1,320 ppm for 6 hr/day, 5 days a week for 13 weeks. Clinical signs, body weights, food consumption, urinalysis, hematologic parameters, serum chemistry measurements, organ weights, necropsy, and histopathological findings were compared between the control and ethyl formate-exposed groups. Locomotor activity decreased during exposure and recovered afterward in male and female rats exposed to 1,320 ppm ethyl formate. Body weight and food consumption continuously decreased in both sexes exposed to 1,320 ppm ethyl formate from week 1 or 3 compared with the control values. The increases in adrenal weight and decreases in thymus weight were noted in both sexes exposed to ethyl formate at 1,320 ppm. Degeneration, squamous metaplasia of olfactory epithelium in the nasopharyngeal tissue, or both were noted in the male and female rats at 1,320 ppm and female rats at 330 ppm ethyl formate. Taken together, our results indicate that ethyl formate-induced changes were not observed in male and female rats at 330 and 66 ppm, respectively. This indicates that exposure to ethyl formate at concentrations below 66 ppm for 90 days is relatively safe in rats. This is the first report of a full-scale repeated inhalation toxicity assessment in rats and could contribute to controlling occupational environmental hazards related to ethyl formate.

• Toxicological Research
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• v.14 no.2
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• pp.129-141
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• 1998

Toxic effects of 2-bromopropane (2-BP) on the hematopoietic system and testis were investigated in male Srague-Dawley (SD) rats. 80 male SD rats, 5 weeks old, were treated with 2-BP in corn oil at levels of 0, 100, 330 and 1,000 mg/kg/day for 4 weeks orally. 10 animals from each group were maintained for additional 8 weeks following the treatment. In addition, 60 male SD rats were divided into 2 groups and administered 2-BP in corn oil at levels of 0 and 1,000 mg/kg/day orally and sacrificed after 1. 2 and 3 weeks of treatment. Clinical observation. body weight changes, food consumption, organ weight changes. hematology, serum chemistry and histopathology of the testis were performed in the study. No clinical sign and mortality were observed in the study. The body weights were significantly reduced with the treatment but gradually recovered. The relative organ weights of the testis and thymus significantly decreased in both of the groups treated with 1,000 mg/kg/day for 3 and 4 weeks. In the recovery groups, organ weights of the testis and epididymis were significantly reduced in both of the groups treated with 330 and 1,000 mg/kg/day. Platelets and reticulocytes were significantly reduced in both of the group treated with 1.000 mg/kg/day for 3 and 4 weeks. While red blood cells were de-creased but mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were increased in the recovery group. Significant increase of chloride was observed in all of the treatment groups except the recovery groups, and calcium was significantly increased in both of the groups treated with 1,000 mg/kg/ day for 3 and 4 weeks. On the other hand. there were significant decreases in alanine aminotransferase (ALT) and aspatate aminotransferase (AST) in most of groups treated with 1.000 mg/kg/day. In the testis. the spermatogonia in stages I-VI were mostly depleted and the spermatocytes in stages VII-VIII were de-generated or necrotized at week 1 after treatment of 2-BP. The degeneration of germ cells and the a-trophy of seminiferous tubules became more severe in time-dependent and dose-dependent manners. The damaged tubules showed regeneration in part. however. they did not appear to be completely recovered within 8 weeks of the recovery period. On the basis of the results. it is suggested that 2-BP would cause toxicities in hematopoiesis by possibly interfering the production of red blood cells and platelets and in spermatogenesis by the destruction oj spermatogonia in SD male rats.

• Journal of the Korean Society of Food Science and Nutrition
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• v.35 no.9
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• pp.1178-1184
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• 2006

This study was carried out to investigate the effect of ethanol extract of antler velvet (EAV) on common serum chemistry panels and histopathological change in rats exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Administration of TCDD ($50{\mu}g/kg$ body weight) induced significant decrease in platelet count (p<0.01), creatine phosphokinase (CPK, p<0.01), lactatate dehydrogenase (LDH, p<0.05) and glucose (p<0.05) levels and increase in hemoglobin (p<0.05), aspartate aminotransferase (AST, p<0.01), alanine amino transferase (ALT, p<0.05) and lipase activities (p<0.05), and blood urea nitrogen (BUN, p<0.05), triglyceride (p<0.01) and low density lipoptotein cholesterol (LDL-C, p<0.05) levels. However, pretreatment of EAV at daily dose of 20 mg/kg b.w. from 1 wk before TCDD exposure for 5 wks attenuated the abnormality of the overall serum chemistry panels but statistical difference between TE and TA groups was observed only in testicular weight (p<0.01), LDH activity (p<0.05), glucose (p<0.05) and lipase activity (p<0.01). In addition, TCDD induced significant histopathological changes including swelling, fatty metamorphosis, and vacuolar degeneration in liver; edema in proximal and distal convoluted tubules, and glomerulus in kidney; severe atrophy of red purple and appearance of significant number of macrophage in spleen; prominent atrophy and decrease in immune cells in thymus. On the other hand, administration of EAV attenuated histopathological damage induced by TCDD. These results further suggest that administration of EAV attenuates TCDD induced testicular, liver, pancreatic, hematopoietic and nephrotic toxicities in rats.

• Korean Journal of Agricultural Science
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• v.2 no.1
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• pp.9-47
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• 1975

These experiments were caried out to study the effects of caponization and various hormone treatments upon meat production and improvement of meat quality of growing chicken. Sixtyseven days old 160 New Hampshire cockerels were treated and growth rate, carcass yield, change of weight of individual organs, meat composition and change of amino acid were measured and analysed. Otherwise change of testis and thyroid gland by hormone treatment were investigated histologically. The results obtained were as follows. 1. The effectst of caponization and hormone treatment upon meat production were; 1) Body weight of cockerels in D. E. S. group without caponization was increased. upon 96.86% than initial period and A. C. T. H. group was 104.22% but other groups and all carponization groups were lighter than those of control group. 2) Weekly body gain of D. E. S. group without caponization was best showing the significance (102.69 g) and the group with caponization were lower than those groups without caponization. 3) Carcass yield was best in Testo. group without caponization (831.2 g) and the group with caponization were lower than the group without caponization. 4) Carcass rate was highest in A. C. T. H. group with caponization and (67.22%) lowest in Testo. group without caponization (63.37%), but any significance was not recognized. 2. The effects of caponizatitn and hormone treatments upon the coposition of meat and amino acids were; 1) Any significance was not recognized between treated and untreated group about change of moisture, crude protein, crude ash and glycogen contents in meat. 2) Fat co tent in muscle in the all treated groups were higher than that of control group. 3) Extracts of group without caponization were higher than those of groups with caponization. 4) Lysin contents were highest in D. E. S. group with caponization (11. 12/ 16.0 g N) and generelly Testo. group was lower compared with D. E. S. group. 5) Histidine and Arginine contents were higher in the groups with caponization than without caponization. 6) Aspartic acid content were higher in D. E. S. group and A. C. T. H. group without depend on caponization. 7) Treonine content was higher in Testo. group without caponization and in the group with caponization and without hormone treatment compared with those of control group without caponization. 8) Serine content was decreased in the group with caponization and increased by D. E. S. and A. C. T. H treatment groups and glutamic acid was also decreased in Testo. group with out caponization. 9) Cystine content was decreased by Testo. treatment and was not appeared in Testo. group without caponization. 10) Valine content was lower in control group with caponization but significance was not recognized between other groups and control group without caponization. 11) Glycine, Alanine, Methionine. Isoleucine, Leucine, Thyrosine and Phenylalanine contents were not so difference between hormone treated groups and control group without caponization. 3. The effects of caponization and hormone treatment upon the change of organs were: 1) The weight of all organs were heaviest in D. E. S. group without caponization (18.5g) and lightest in A. C. T. H. group without caponization (155. 3g) but no significance was recognized between hormone treatment groups. 2) Heart weight was heaviest in D. E. S. group without caponization (7.46 g) and lightest in Testo. group without caponization (5.95 g). 3) Liver weight was heaviest in D. E. S. group without caponization(32.89g) and lightest in hormone untreated group with caponization(29.66g). Significance was not recognized. 4) Spleen weight was heaivest in Testo. group with caponization (3.22 g) and lightest in D. E. S. group without caponization(2.00g) in contrast with the other groups. High significance was recognized among the groups (P<0.01). 5) Cloacal thymus weight was lightest in D. E. S. group with or without caponization compared with control group without caponization. High significance was recognized among the groups. 6) Muscle fat content was not appeared in A. C. T. H. group with caponization, but it was highly increased in D. E. S. group with or without caponization. 7) Testis weight was lightest in D. E. S. group (0.38g) compared with control group (2.66g). Significance was recognized among the groups. 8) Large intestine, small intestine and cecum weight and length were heavier and longer in D. E. S. group without caponization and control group without caponization was lighter than those of hormone treated groups. 4. The effects of caponization and hormone treatment upon histological change of testis and thyroid gland: 1) The histological change of testis was significantly appeared in D. E. S. group that seminifirous tubles was slowly atrophied, the funtion of spernatogenesis was ceased, spermatocyte was changed as degeneration by pyknosis and karyorrhexis and interstitial cell was also atrophied, but in Testo. and A. C. T. H. group were similar as control group. 2) The histological change of thyroid gland in Testo. and A. C. T. H. groups without caponization were similar to that of control group without caponization, but in D. E. S. group without caponization, was changed squamously. Thyroid gland of the groups with caponization, epithelium of was atrophied and changed squamously as degeneration by pyknosis and karyorrhexis and the function of thyroid gland was slowly ceased in colloid and in hormone treated group with caponization.