[abstract] SUSCEPTIBILITY OF ALTITUDE-ACCLIMATIZED MICE TO ACUTE OXYGEN TOXICITY.

Abstract

The influence of acclimatization to altitude on the relative susceptibility to acute oxygen poisoning was determined in 288 adult female mice. Mice were held at chamber altitudes of sea level 5,000 or 15,000 feet. After acclimatization periods of one, two, four or eight weeks, the mice were exposed to oxygen at high pressures (OHP) of four, six or nine atmospheres absolute and the times to convulsion and death recorded. Factorial analysis of variance indicated that the times to convulsion and death were shorter the higher the altitude (P less than 0.005) as well as the higher the OHP level. The duration of acclimatization did not significantly affect the time to convulsion but the time to death decreased (P less than 0.025). Onset of convulsions and death were independent of body weight. Our experimental design did not allow us to gather information which might explain these effects of altitude on susceptibility to oxygen toxicity in mice, but the effects may well have practical implications in hyperbaric oxygen treatment of patients who are residents at even moderate altitudes.