title: Glutathione peroxidase, glutathione S-transferase and glutathione reductase activities in normal and neoplastic human breast tissue.
abstract: Glutathione peroxidase (GSH-Px), glutathione S-transferase (GSH-Tr) and glutathione reductase (GSSG-Rx) activities have been determined in normal and neoplastic human breast tissues. Large interindividual variations in the activities of all enzymes tested were found in both tumor and non-tumor specimens. In general a significant increase in the activities of the 3 enzymes was found in tumors, whereas in fibroadenoma they were as high as in healthy tissues. When a comparison was made between normal and neoplastic tissues of the same individual, GSH-Tr and GSSG-Rx activities were found to be higher in 15 and 11 cases, respectively, out of 17. GSG-Px activity was higher in all cases. From measurement of GSG-Px activity with both H202 and cumene hydroperoxide, it was deduced that human breast contains only the selenium-dependent form.
mesh_terms: D000232:Adenofibroma / Q000201:enzymology*; D001940:Breast / Q000201:enzymology; D001943:Breast Neoplasms / Q000201:enzymology*; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000201:enzymology*; D005260:Female; D005348:Fibrocystic Breast Disease / Q000201:enzymology; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism*; D005980:Glutathione Reductase / Q000378:metabolism*; D005982:Glutathione Transferase / Q000378:metabolism*; D006801:Humans; D012643:Selenium / Q000378:metabolism
chemical_list: D005979:Glutathione Peroxidase; D005980:Glutathione Reductase; D005982:Glutathione Transferase; D005978:Glutathione; D012643:Selenium