Role of cytochrome P-450 2E1 in ethanol-, carbon tetrachloride— and iron-dependent microsomal lipid peroxidation

✍ Scribed by Tirso Castillo; Dennis R. Koop; Seiichiro Kamimura; George Triadafilopoulos; Hidekazu Tsukamoto

• Publisher: John Wiley and Sons
• Year: 1992
• Tongue: English
• Weight: 608 KB
• Volume: 16
• Category: Article
• ISSN: 0270-9139
• DOI: 10.1002/hep.1840160423

✦ Synopsis

This study investigated the role of cytochrome P-450 2E1 in enhanced microsomal lipid peroxidation in experimental alcoholic liver disease. W e also examined the contribution of this isoform to the increased microsomal injury in alcoholic liver disease caused by carbon tetrachlorideinduced or iron-induced oxidant stress. Adult male Wistar rats were intragastrically infused with a high-fat diet and ethanol or glucose for 16 wk; this resulted in hepatic lipid peroxidation and fibrogenesis in the ethanol-fed animals. Microsomes were isolated by differential centrifugation in the presence of 100 pmoUL deferoxamine, washed twice in buffer without deferoxamine and incubated in the absence or presence of ethanol (50 mmoUL), carbon tetrachloride (150 pmoUL), ferric citrate (60 Fmol/L) or ferric citrate plus ethanol at 37" C for 30 min in an NADPH-generating system. The basal rate of lipid peroddation in microsomes isolated from ethanol-fed rats was increased by 52% compared with that in microsomes from controls. Carbon tetrachlorideinduced and ferric citrateinduced lipid peroxidation were also accentuated in microsomes from ethanol-fed rats, by 76% and 108%, respectively. Ethanol added in uitro significantly reduced basal (-58%) and ferric citrateinduced ( -48%) lipid peroxidation in microsomes from ethanol-fed rats, whereas it had an insignificant effect on that in control microsomes. In fact, this protective effect of ethanol on microsomes from ethanol-fed rats resulted in attenuation of the difference in the level of microsomal lipid peroxidation between the two groups. P-450 2E1 IgG antibody added to the incubation completely blocked the enhanced lipid peroxidation observed in microsomes from ethanol-fed rats under the basal, ferric citrateinduced and carbon tetrachlorideinduced conditions. Immunoblot analpis of microsomal proteins with