TOXICITY OF HYPEROXIA AND HIGH-PRESSURE ON C3H 10T1/2 CELLS AND EFFECTS ON CELLULAR GLUTATHIONE/

Saturation diving involves the exposure of humans to elevated partial pressure of oxygen (PO2) and high ambient pressure. The present study is part of a research program that focuses on how such conditions affe ct basal cellular functions. C3H/10T1/2 Cl 8 mouse embryo fibroblasts were exposed to 20-80 kPa O-2 in a He-O-2 mixture at 0.1 and 5.0 MPa a mbient pressure for 24-72 h. Elevated PO2 had severe toxic effects on the cells, and there was an additional effect of high pressure on net cell growth. A persistent reduction of cell growth rate after the end of exposure to HeO2 was noted, suggesting genetic effects. We observed no effects of the ambient pressure per se in this respect. High PO2 i ncreased the cellular glutathione level reaching a plateau approximate ly 100% above control at a PO2 of 60 kPa. No alteration of the glutath ione redox status was observed, and high ambient pressure per se had n o significant effect on the cellular glutathione content. The increase d glutathione content did not completely protect the cells against tox ic injury of high oxygen levels.