Immunohistochemical localization of glutathione S-transferases in livers of untreated rats.

Sheep antibodies raised against three isoenzymes of glutathione S-transferase (EC 2.5.1.18), transferases B, C, and E, which were isolated and purified to apparent homogeneity from rat liver, have been employed to localize these enzymes at the light microscopic level within livers of untreated rats. Using these antibodies in an unlabeled antibody peroxidase-antiperoxidase staining technique, each glutathione S-transferase was detected immunohistochemically within parenchymal cells throughout the liver lobule. In addition, immunohistochemical staining for transferases C and E, but not for transferase B, was observed within bile duct epithelium. While all parenchymal cells were stained with each glutathione S-transferase antibody, the patterns of immunohistochemical staining intensity observed across the liver lobule with the three anti-transferases were not uniform: parenchymal cells within the centrilobular region were more intensely stained for each lobular region were more intensely stained for each isoenzyme than were those within the midzonal and periportal regions of the lobule. The results of this immunohistochemical study thus demonstrate that glutathione S-transferases are not distributed uniformly throughout the liver lobule and that each transferase is present in the greatest concentration within the centrilobular region of the lobule.