Activity of antioxidant enzymes and lipid peroxidation in intact and mutagen-treated NZW mice

Abstract

Catalase and superoxide dismutase activities in the liver of NZW mice are 29.3 μmol H₂O₂/min×mg protein and 10.6 U/mg protein, respectively. The rate of accumulation of lipid peroxidation (LPO) products is low within the first 60 min of incubation of liver homogenates with ascorbate and then rapidly increases. A similar process is observed with Fe+ascorbate system, where LPO rate is markedly higher and lag-period lasts 10 min. Under the action of cyclophosphane the activity of catalase increases by 32%, while that of superoxide dismutase decreases by 46%, which is accompanied by a decline in the sensitivity of liver tissue to LPO induction. When LPO is inducedin vitro by ascorbate, lag-period decreases 2-fold, while the rate of accumulation of LPO products increases by 38% and their maximum level by 35% compared with the control. Similar processes develop in the Fe+ascorbate system. Dioxydine induces no significant changes in the activities of catalase and superoxide dismutase as well as in LPO product accumulation in the ascorbate and Fe+ascorbate systems.