Evidence for a defective mitochondrial membrane in 1,2-dimethylhydrazine-induced colon adenocarcinoma in rat: Enhanced lipid peroxidation potential in vitro

Abstract Enhanced lipid peroxidation potential was measured in Holtzman rat colon tumors induced by chronic subcutaneous injection of 1,2-dimethylhydrazine as compared with normal colonic tissue. The peroxidation potentials were determined in the mitochondrial cellular components by measuring the ferrous-ascorbate induced formation of malondialdehyde. The tumor mitochondria were found to peroxidize at a rate 8–10-fold higher than the comparable normal tissue components. In addition, we found that the mitochondria from the cancer cells exhibited reduced NADH-cytochrome c reductase activity. These observations suggest an involvement of non-enzymatic free radical flux in DMH-induced carcinogenesis, which may be the result of structurally altered mitochondrial membranes.