IMMUNOLOCALIZATION OF MICROSOMAL GLUTATHIONE-S-TRANSFERASE IN RAT-TISSUES

Distribution of microsomal glutathione transferase (mGST) protein in r at tissues was investigated by immunohistochemistry. Studies on the lo calization of mGST are of interest because of its involvement in the d etoxication and bioactivation of xenobiotics. mGST antigen was detecte d in the cytoplasm of some hepatocytes and in bile ducts. In kidney, f ocal staining of mGST was observed in distal tubules and collecting du cts. Cerebral cortical and cerebellar Purkinje neurons showed good imm unoreactivity, and nuclear staining was observed in the choroid plexus . The antigen was detected in epithelial cells of respiratory bronchio les and in the crypt cells of the duodenum. Exocrine cells of the panc reas stained for mGST. Nuclear immunostaining for this protein was obs erved in primary spermatocytes. mGST antigen was detected in the cytop lasm of the adrenal medulla as a granular stain. Leydig and Sertoli ce lls in testis also stained for the antigen. Distribution of mGST prote in differs from that observed with cytosolic transferases and may be i mportant in determining cell-selective susceptibility to xenobiotics.