title: The decrement of carcinogenesis by dietary selenium and expression of placental form of glutathione-S-transferase in rat glioma.
abstract: Supranutrition dietary levels of the element selenium (Se) that have been shown to reduce or retard tumor development resulting from transplantation. The rat placental form of glutathione-S-transferase (GST-p) has been reported to be a good marker for pre-neoplastic or neoplastic lesions. Four groups of rats with glioma were exposed to Se-free, 0.05, 2.0, and 4.0 ppm sodium selenite GST-p was investigated. Normal brain tissue did not differ significantly in all groups. In contrast, GST-p in tumor was significantly higher in Se-free and 4.0-ppm groups compared to 0.5- and 2.0-ppm groups. The concentration of Se in normal brain tissue did not differ significantly in Se-supplement groups. By contrast, Se in tumors was significantly higher in the 0.5- and 2.0-ppm groups compared to the Se-free and 4.0-ppm groups. Mean group survival at 30 d after treatment was determined and compared with previous dietary Se. Survival was significantly longer in the 0.5- and 2.0-ppm groups than in the Se-free and 4.0-ppm groups. The 2.0-ppm group had enhanced survival, similar to the 0.5-ppm group. The Se-free and 4.0-ppm groups might have no protection against carcinogenesis.
authors.affiliation: Department of Social Medicine, Kyoto University, Japan.
authors.forename: Z
authors.initials: Z
authors.lastname: Zhang
authors.forename: M
authors.initials: M
authors.lastname: Kimura
authors.forename: Y
authors.initials: Y
authors.lastname: Itokawa
mesh_terms: D000818:Animals; D016588:Anticarcinogenic Agents / Q000008:administration & dosage; D001921:Brain / Q000378:metabolism; D001932:Brain Neoplasms / Q000201:enzymology / Q000378:metabolism / Q000517:prevention & control*; D004032:Diet; D005910:Glioma / Q000201:enzymology / Q000378:metabolism / Q000517:prevention & control*; D005982:Glutathione Transferase / Q000378:metabolism*; D008297:Male; D009368:Neoplasm Transplantation; D010920:Placenta / Q000201:enzymology*; D051381:Rats; D017208:Rats, Wistar; D012643:Selenium / Q000008:administration & dosage*; D014407:Tumor Cells, Cultured
chemical_list: D016588:Anticarcinogenic Agents; D005982:Glutathione Transferase; D012643:Selenium