Metabolism of Oxygen Free Radicals in the Regenerating Liver of Rats

Background/Aims: To know the metabolism of oxygen free radicals in the regenerating liver, the 70% (median and left lateral lobes) partial hepatectomy was performed in the Sprague-Dawley rats. Methods: The original livers were obtained immediately after the partial hepatectomy, while the regenerating livers were obtained at 3 days after the partial hepatectomy. The levels of xanthine oxidase, superoxide anion, antioxidant enzymes, hydrogen peroxide, and malondialdehyde were measured. RT-PCR for superoxide dismutase was also performed. Results: Compared to the original livers, the regenerating liver showed higher levels of xanthine oxidase, superoxide dismutase, catalase, glutathione peroxidase superoxide production, and malondialdehyde and lower level of hydrogen peroxide. RT-PCR did not show any significant change. Conclusions: The results suggest that malondialdehyde level is increased by xanthine oxidase via the increased production of superoxide anion. Superoxide dismutase activity is induced by the increase of superoxide anion. The increase of catalase and glutathione peroxidase levels causes the depletion of hydrogen peroxide level in the regenerating liver.