[Oxygen toxicity in a mixture with helium].

A 3-day exposure of mice to a 20%--80% He-O2 environment at 28--30 degrees C led to an earlier decrease of gas exchange, a faster development of pulmonary inflammatory changes, and an earlier death of the animals as compared with an exposure to similar N2-O2 and He-O2 atmospheres at room temperature. The possible role of the indifferent gas in the toxic effect of oxygen on the animal body is discussed.