Accumulation of products of lipid peroxidation in spontaneous liver tumors of C3H/HeN mice

To study the implication of oxidative stress in liver tumors, quantitative analysis of products of lipid peroxidation, which are reactants of 2-thiobarbituric acid (TEA) in the TEA method, was carried out in both neoplastic and intact liver tissues of C3H/HeN mice. All liver tumors were derived spontaneously at the age of 15-18 months. We found that TEA value in neoplastic foci was increased about 10-fold higher than that in intact liver counterparts. Moreover, antioxidant activities such as catalase, glutathione peroxidase and superoxide dismutase were all decreased in neoplastic foci in comparison with those in respective intact liver counterparts. We also established a histochemical method to detect peroxides and applied this method to the liver tumors. Peroxides were stained abundantly in the vacuolated cells of neoplastic foci. Fragments of condensed peroxides were occasionally seen in some vacuolated cells. Therefore, peroxide staining described here should be useful to identify the localization of peroxides in the tissues.