Immunohistochemical localization of human liver glutathione S-transferase (GST) isozymes with special reference to...

The products of three human glutathione S-transferase (RX:glutathione R-transferase, EC 2.5.1.18) (GST) loci (GST 1, GST 2 and GST 3) were purified and their immunohistochemical localization in liver was studied with special attention to the polymorphism of GST1 (neutral isozyme). The GST1 was homogeneously stained in cytoplasm of hepatocytes throughout the lobule of liver showing GST1 1, GST1 2 and GST1 2-1 phenotypes. However, none of the hepatic tissue showing GST1 0 phenotype was stained. Immunohistochemical staining of GST2 (basic isozyme) was distributed in the cytoplasm of hepatocytes homogeneously throughout the hepatic lobule in all cases and the strong staining intensity was also demonstrated in nucleus. GST3 (acidic isozyme) was strongly stained in biliary epithelium, while staining of hepatocytes was not apparent. These results indicate that the human liver GST isozymes exhibit significant difference in their inter-individual, specific cellular and organellar distribution.