Effects of hyperoxia on growth of experimental lung metastasis.
Mice were given i.v. injections of various tumor cell lines and, beginning 24 h later exposed for 3 weeks to 70% oxygen. Hyperoxia reduced the number of lung colonies derived from MT-7 cells (originally a mammary carcinoma) and of the lung-tumor derived cell lines 498 and Line-1 early passage. Lung colonies derived from Line-1 late passage, lines M109, B16-F10 and Lewis lung carcinoma were oxygen resistant. Lung metastases following i.m. injection of MT-7 cells were oxygen-sensitive and metastases derived from B16-F10 cells or Lewis lung carcinoma were oxygen resistant. Pre-exposure of mice for 48 h to 100% oxygen enhanced colony formation for all cell lines examined whereas exposure to 100% oxygen after i.v. injection only curtailed the growth of the cell lines previously shown to be sensitive to 70% oxygen. There was no correlation between oxygen sensitivity or resistance and the levels of total glutathione or activities of superoxide dismutase (SOD), glutathione reductase or peroxidase or glucose 6-phosphate dehydrogenase in the cell lines. However, upon injection in mice a resistant cell line increased its anti-oxidant defense mechanisms while growing in vivo whereas a sensitive cell line failed to show such adaptation.
Margaretten
N C
NC
Biology Division, Oak Ridge National Laboratory, TN 37831.
Witschi
H R
HR
D000818:Animals; D005978:Glutathione / Q000032:analysis; D005980:Glutathione Reductase / Q000032:analysis; D008175:Lung Neoplasms / Q000556:secondary*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D010100:Oxygen / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000032:analysis; D014407:Tumor Cells, Cultured
D013482:Superoxide Dismutase; D005980:Glutathione Reductase; D005978:Glutathione; D010100:Oxygen