Immunohistochemical localization of alpha and pi class glutathione transferases in normal human tissues

The distribution of alpha and pi class glutathione transferases in autopsy and biopsy samples of normal human tissues was investigated by immunohistochemistry. The class alpha glutathione transferases exhibited restricted distribution. Intensive staining was visible in all hepatocytes, in kidney proximal tubular cells, in the zona reticularis of adrenal cortex and in Leydig cells of testis. Staining of lesser intensity could also be observed in the gastrointestinal epithelium, exocrine pancreas and some bile and pancreas ducts. In colon and gall bladder only nuclei were stained, but in the other tissues both nuclei and cytoplasm contained alpha class glutathione transferases. Glutathione transferase pi exhibited a more general distribution and could be observed in epithelia of the respiratory, gastrointestinal and urinary tracts, in all endocrine cells investigated, and also in the exocrine glands of prostate, in smooth muscle, adipocytes, blood vessel endothelium and placenta. It was also visible in the Schwann cells of peripheral nerves and in the choroid plexus. In gall bladder and colon only nuclei were stained, while in the intrahepatic bile ducts only cytoplasm was stained. All other positive cells exhibited glutathione transferase pi in both nuclei and cytoplasm.