Effects of hyperoxia on B16–F10 cells in vivo

Abstract

The in vivo effects of hyperoxia were studied in lung colonies formed by B16–F10 melanoma cells in mice. Several antioxidant defenses were found to change with in vivo exposure: glutathione reductase and glucose-6-phosphate dehydrogenase activities decreased as compared with levels in the cultured cells, glutathione peroxidase activity dramatically increased, and Mn-superoxide dismutase activity and levels of total glutathione were similar in vivo and in vitro. Exposure of tumor-bearing animals to 70%, O 2 for 3 weeks did not alter the antioxidant defenses measured in the tumors. One hundred percent O 2 exposure did not affect either initial arrest or subsequent retention of radiolabeled B16–F10 cells in the lung. Likewise, hyperoxia did not appear to alter cell division in B16–F10 cells growing in the lung. These results are consistent with our previous studies indicating that the B16–F10 cell line is resistant to levels of O 2 in vivo that adversely affect other tumor cell lines.