• 대한의생명과학회지
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• 제7권3호
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• pp.99-102
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• 2001

Toluene is mainly metabolized in liver by oxidative pathway. Oxigen free radicals occur through the process of toluene metabolism Therefore it causes tissue and cell min by the oxygen free radicals from the metabolism of toluene. Melatonin acts as a highly efficient free radical scavenger that protects cells from damage by oxygen free radicals. To test this hypothesis, toluene hepatotoxicity was induced by an abdominal injection of toluene. To see if the melatonin protects the rat's liver, melatonin was administrated orally, at the time of each toluene injection. Aspartate aminotransferase(AST), alanin aminotransferase(ALT), latic dehydrogenase(LDH) and alkaline phosphatase(ALP) levels in serum were measured to estimate hepatic function. Malondialdehyde(MDA), which gives an indirect index of oxidative injury was also measured. Hippuric acid is the last metabolic Production of toluene was measured by HPLC. There were significantly higher in AST, ALT, LDH, MDA and hippuric acid in toluene group, but there were no significant difference in melatonin group except ALT and hippuric acid. There was significantly lower in ALP level in toluene group, but there was no significant difference melatonin group, suggesting a significant hepatotoxicity due to oxygen free radicals through the process of toluene metabolism Melatonin treatment significantly protected hepatic function and free radical-mediated injury in the liver against toluene-induced changes. Accordingly, this study shows that melatonin is helpful in protecting liver injury by acute toluene intoxication.

• Toxicological Research
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• 제17권1호
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• pp.33-39
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• 2001

To evaluate the skin toxicity oj topical toluene application, toluene (35 mg/$cm^2$) was sequentially applied to the portion rat skin for five days. The topical toluene application resulted in increased xanthine oxidase activity and CYP content, and significantly decreased superoxide dismutase and glutathione peroxidase activities at five days in rat skin. Especially catalase activity was remarkably decreased in toluene-applied rat skin. And benzylalcohol dehydrogenase activity showed also a significant decrease in toluene-applied skin. On the other hand, histopathological ultrastructural examination revealed disrupted epidermal basement membrane, rared intercellular adhensions and degenerated keratin layer due to topical toluene application. Increased deposit of cerrous perhydroxide resulted from reaction with $H_2O_2$was abserved in toluene-treated animals. These results indicate that oxygen free radical may be responsible for ultrastructural changes in skin tissue by toluene application to rat skin.

• Korean Chemical Engineering Research
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• 제54권5호
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• pp.665-670
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• 2016

본 연구에서는 톨루엔 분해 균주인 Pseudomonas putida와 아세트산 분해 균주인 Cupriavidus necator에 무세포 효소 시스템(cell-free enzyme system)을 적용하여 톨루엔과 아세트산에 대한 분해 가능성을 확인하는 실험을 수행하였다. P. putida는 톨루엔 존재 하에서만 toluene dioxygenase를 생성하여 톨루엔을 cis-toluene dihydrodiol로 분해하며, C. necator는 acetyl coenzyme A synthetase-1을 생성하여 아세트산을 acetyl CoA로 전환시켜 생존에 필요한 ATP나 생분해성(biodegradable) 고분자인 Polyhydroxyalkanoate (PHA)를 합성한다. P. putida의 톨루엔 분해 효소인 toluene dioxygenase는 유도효소이기 때문에 toluene dioxygenase 생성 전과 후로 나누어 실험을 진행하였다. P. putida의 톨루엔 분해능력 확인을 위한 gas chromatography (GC) 분석 결과, 대조군과 toluene dioxygenase 생성 전인 실험군 1에서는 검출된 톨루엔의 양이 거의 유사하였으나, toluene dioxygenase 생성 후인 실험군 2에서는 검출된 톨루엔의 양이 대조군 및 실험군 1에 비해 감소하였다. 또한 C. necator의 아세트산 분해능력 확인을 위한 gas chromatography-mass spectrometer (GC-MS) 분석 결과, 무세포 효소 시스템을 적용한 실험군에서는 아세트산에 대한 피크가 검출되지 않았다. 따라서 P. putida와 C. necator는 무세포 효소 시스템 적용 후에도 톨루엔 및 아세트산 분해 능력이 유지되었으나, P. putida는 무세포 효소 시스템을 적용하기 전에 유도 효소를 생성하는 과정이 필요하다.

• Preventive Nutrition and Food Science
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• 제5권2호
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• pp.105-108
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• 2000

To evaluate an effect of oxygen free radical on the toluence metabolism, the rats were fed on a tungstate sup-plemented diet(0.75g of tungstate included in 1kg of standard diet) or a standard diet. To the present xanthine oxidase deficient animal model, toluene(0.15ml/100g of body weight) was injected and then the animals were sacrificed after 24 hrs to determine the toluene metabolizing enzyme activities and toluene metabolite, hippuric acid concentration. The increasing rate of urinary hippuric acid concentration was significantly(p<0.01) higher in tungstate fed animals than in standard diet fed ones. Hepatic cytochrome P_450 contents were significantly higher(p<0.01) in tungstate fed animals than in standard diet fed ones. And tungstate fed animals showed a ten-dency of higher activities of benzylalcohol dehydrogenase while a significantly higher activites of benzaldehyde dehydrogenase (p<0.01) than standard diet fed animals. In conclusion, the more possibly reduced oxygen free radical in toluene-treated rats fed with a tungstate supplemented diet than in those fed with a standard diet would be responsible for the enhancement of toluene metabolism.

• 한국환경보건학회지
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• 제27권2호
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• pp.22-29
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• 2001

To evaluate the cutaneous injury in liver damaged rats by toluene application to the skin, toluene(35mg/㎤) was sequentially applied for 5 days to the dorsal skin of liver damaged rats with $CCl_4$ (6 times ever other day:0.1$m\ell$/100 g body weight-50% $CCl_4$in olive oil). The cutaneous ultrastructural changes were unexoectably not observed in liver from $CCl_4$-treated rats although necrotic liver damage appeared under light microscope. In these animals by the application of toluene to rat skin the cutaneous xanthine oxidase activity was significantly increased(p<0.05), but cytochrome P450 content was not different from that of the control or only $CCl_4$-treated rats. On the other hand, the cutaneous superoxide dismutase and catalase activities in liver damaged animals were significantly respectively(p<0.05, p<0.001), decreased by toluene application to the skin compared with control and especially the former enzyme activity was significantty decreased(p<0.01), compared with that of liver damaged rate rat but glutathione peroxidase, glutathione-S-transferase activities were not significantly different from those of the control or liver damaged rats. Futhermore, the reduced gluathione content of skin was also significantly decreased by toluene application to the liver damaged animals. In conclusion, the great deposits of cerrous peroxide and ultramorphological changes in skin tissue of liver damaged animals by toluene application may be responsible for the oxygen free radical.

• Toxicological Research
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• 제11권2호
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• pp.289-294
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• 1995

This study was designed to observe the effect of tohiene pretreatment on leukocyte variation in whole blood and the oxygen free radical generating, scavenging enzyme activities in neutrophil of bacteria infected rats. Toluene was administered 7 times intraperitoneally at levels of 9.45 mM/kg body weight to the rats and then infected with S. aureus $2\times10^7$ cfu/ml. The toluene treated-rats showed the significantly decreased numbers of lymphocyte and monocytes, but the similiar numbers of neutrophils with the control. Furthermore the increased neutrophils in blood of bacteria infected rats were reduced by the toluene pretreatment. Concomitantly the increased activities of xanthine oxidase and superoxide dismutase in neutrophil of bacteria infected rats were also decreased by the toluene pretreatment. On the other hand, injection of benzaldehyde to rats also led to similiar results in the count of leukocytes, xanthine oxidase and superoxide dismutase activities of neutrophil with those of toluene treated rats. These data suggest that toluene and its intermediate metabolite, benzaldehyde influence on the phagocytosis and defence mechanism of neutrophil.

• 대한의생명과학회지
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• 제7권1호
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• pp.47-51
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• 2001

To investigate an effect of the topical toluene application to .at skin on the liver injury, toluene (35 mg/$cm^2$) was sequentially applied for 3 or 5 days to rat skin and then the animals were sacrificed. 5 day toluene-treated rats showed the slight increase of live. weight per body weight(%) compared with control. Serum levels of xanthine oxidase and alanine aminotransferase activity were significantly increased both in 3 days and 5 days toluene-treated animals compared with control. In the histopathological findings, cytoplasmic degeneration of hepatocytes around the central vein was noted in the liver of rats applied with toluene to the skin. These results indicate toluene application to rat skin feds to somewhat slight liver injury. On the other hand, the hepatic benzylalcohol or aldehyde dehydrogenase activities were significantly decreased by toluene application to rat skin. In conclusion, the liver min was induced by toluene application to rat skin, and it can be hypothesized that accumulation of benzaldehyde in liver cell may be responsible for liver injury.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.123-123
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• 2010

The hydrophobic coating for multi-walled nanotubes was treated with toluene and trimethylchlorosilane glow discharge plasma under low pressure, and the hydrophobic surface of the treated MWCNT was investigates. In order to investigate the effects of -CH components from the toluene and TMCS glow plasma, we conducted on the total surface free energies of the MWCNT powder, which was calculated by measuring the contact angle between the cushion of MWCNT powder and the probe liquids. The total surface free energies were determined by Owens-Wendt equation and drastically decreased.

• 대한화학회지
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• 제43권3호
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• pp.251-256
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• 1999

여러 온도와 압력에서 톨루엔의 점성도를 공낙하법에 의하여 결정하고 톨루엔의 점성도에 대한 온도 및 압력 의존성을 연구하였다. 톨루엔의 점성 흐름에 관한 엇갈림 변형력으로부터 엇갈림 자유 에너지, 엇갈림 엔트로피, 엇갈림 엔탈피 등을 정의하여 압력 변화에 따르는 열역학적 성질의 변화를 고찰하였다. 실험적으로 결정된 엇갈림 자유 에너지, 엇갈림 엔트로피, 엇갈림 엔탈피 등을 온도 상승에 의한 톨루엔 분자들의 열운동 효과와 압력 증가에 의한 밀도 증가 및 분자의 입체 효과에 의하여 설명하였다.

• 접착 및 계면
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• 제19권1호
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• pp.1-4
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• 2018

본 연구에서는 부착력 향상 및 모바일 기기용 toluene-free 프라이머를 제조하기 위해 클로로프렌 고무 (CR)에 실리카 나노입자를 분산시켜 CR/silica 복합체를 제조하였다. CR/silica 복합체는 FT-IR, SEM, EDS 등을 이용하여 물성을 평가하였다. SEM을 통해 실리카 나노입자의 함량이 4 phr일때 가장 균일하게 분산되어 있는 것을 확인하였다. 접촉각과 연필경도측정을 통해 실리카 함량이 증가할수록 소수성을 띠는 것과, 연필경도가 증가함을 나타내었다. 부착력 결과 역시 실리카 함량이 4phr일때 가장 높았으며, 실리카가 함유되지 않은 P-0에 비해 50% 증가함을 확인하였다.