title: Role of CYP2E1 in thioacetamide-induced mouse hepatotoxicity.
abstract: Previous experiments showed that treatment of mice and rats with thioacetamide (TAA) induced liver cell damage, fibrosis and/or cirrhosis, associated with increased oxidative stress and activation of hepatic stellate cells. Some experiments suggest that CYP2E1 may be involved in the metabolic activation of TAA. However, there is no direct evidence on the role of CYP2E1 in TAA-mediated hepatotoxicity. To clarify this, TAA-induced hepatotoxicity was investigated using Cyp2e1-null mice. Male wild-type and Cyp2e1-null mice were treated with TAA (200 mg/kg of body weight, single, i.p.) at 6 weeks of age, and hepatotoxicity examined 24 and 48 h after TAA treatment. Relative liver weights of Cyp2e1-null mice were significantly different at 24 h compared to wild-type mice (p<0.01). Serum levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) in Cyp2e1-null mice were significantly different at both time points compared to wild-type mice (p<0.01). Histopathological examination showed Cyp2e1-null mice represented no hepatototoxic lesions, in clear contrast to severe centriobular necrosis, inflammation and hemorrhage at both time points in wild-type mice. Marked lipid peroxidation was also only limited to wild-type mice (p<0.01). Similarly, TNF-alpha, IL-6 and glutathione peroxidase mRNA expression in Cyp2e1-null mice did not significantly differ from the control levels, contrasting with the marked alteration in wild-type mice (p<0.01). Western blot analysis further revealed no increase in iNOS expression in Cyp2e1-null mice. These results reveal that CYP2E1 mediates TAA-induced hepatotoxicity in wild-type mice as a result of increased oxidative stress.
authors: Department of Pathology, Osaka City University Medical School, 1-4-3 Asahi-machi, Abeno-ku, Osaka 545-8585, Japan.
authors: Jin Seok
authors: JS
authors: Kang
authors: Hideki
authors: H
authors: Wanibuchi
authors: Keiichirou
authors: K
authors: Morimura
authors: Rawiwan
authors: R
authors: Wongpoomchai
authors: Yaowares
authors: Y
authors: Chusiri
authors: Frank J
authors: FJ
authors: Gonzalez
authors: Shoji
authors: S
authors: Fukushima
mesh_terms: D000818:Animals; D001835:Body Weight / Q000187:drug effects; D019392:Cytochrome P-450 CYP2E1 / Q000502:physiology*; D015227:Lipid Peroxidation / Q000187:drug effects; D008099:Liver / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D009929:Organ Size / Q000187:drug effects; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013853:Thioacetamide / Q000633:toxicity*
chemical_list: D013853:Thioacetamide; D019392:Cytochrome P-450 CYP2E1