Immunohistochemical detection of 8-hydroxy-2′-deoxyguanosine in paraffin-embedded sections of rat liver after carbon tetrachloride treatment

To test the applicability of an anti-8-hydroxy-2'-deoxyguanosine (8-OH-dG) antibody for immunohistochemistry using paraffin-embedded sections, carbon tetrachloride (CCl4)-induced rat liver injury was evaluated. Male rats were given a single dose of CCl4 and killed at 6 hr, 12 hr, 1, 2, 3, and 7 days thereafter. Severe centrilobular necrosis was evident at 1 day. At 2 days, moderate mononuclear cell infiltration was: present in centrilobular necrotic regions. Infiltrating mononuclear cells, surrounding sinusoidal endothelial cells and hepatocytes were stained with anti-8-OH-dG antibody at 2 and 3 days. Formation of 8-OH-dG in DNA and 8-oxo-dGTPase mRNA expression were also increased at these time points, the amounts of malondialdehyde and 4-hydroxy-2-nonenal showed 2 peaks at 6 hr and 3 days. The findings suggest that the main contributory factor in the massive hepatic necrosis was increased lipid peroxidation, rather than excessive formation of 8-OH-dG, and that the observed increase in the latter was largely due to infiltrating mononuclear cells. The agreement between biochemical data and the results for immunohistochemical analysis confirms that the anti-8-OH-dG antibody is applicable for detection of cells targeted by free radicals in paraffin-embedded sections and also for investigation of the mechanisms of oxidative damage-related disease, including carcinogenesis.