Figure 4: Analysis of Mn-superoxide dismutase (Mn-SOD), glutathione S-transferase (GSTM1) and β-actin mRNA expression by semiquantitative reverse transcriptase-PCR and immunolocalization of anti-SOD1 and anti- GST1 antibody in hepatocytes. Densitometric analysis of liver Mn-SOD (A) and GSTM1 (B) mRNA expression in control and treated animals. Changes in mRNA are expressed as normalized densitometric units relative to β-actin mRNA. Values are the mean ± SEM. P < 0.05 indicates statistical significance. Immunohistochemistry for the detection of SOD-1 (C- a CG, b G100, c G250, d G500) and GST-1 (D -a G100, b G250, c G500, d PC).