Low temperature worsens mammalian oxygen toxicity.
Oxygen toxicity was assessed in mice exposed to 5 ATA of oxygen. Central nervous system toxicity was measured as the latent period before convulsions, and lung damage estimated by wet and dry weight measurements. Our results confirmed previous findings that hyperbaric oxygen induces hypothermia in animals, and this effect is profound in mice exposed to 5 ATA of oxygen at ambient temperatures of 15 degrees C and 5 degrees C. However, even marked hypothermia had very little effect on the latent times to convulsions in mice. Unexpectedly, the combination of hypothermia and hyperbaric oxygen produced much more severe lung damage than either treatment alone, with a 2.7-fold increase in weight in the 5 degrees C group (average rectal temperature of 16.1 degrees C). These results indicate that hyperoxic-induced hypothermia cannot be considered a protective mechanism against oxygen toxicity and indeed hypothermia can markedly potentiate hyperbaric oxygen toxicity.
School of Physiology & Pharmacology, University of New South Wales, Kensington, Sydney, Australia.
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Jamieson
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Carmody
D000818:Animals; D006931:Hyperbaric Oxygenation / Q000009:adverse effects*; D007035:Hypothermia / Q000209:etiology / Q000473:pathology / Q000662:veterinary*; D008168:Lung / Q000473:pathology* / Q000503:physiopathology; D051379:Mice; D008807:Mice, Inbred BALB C; D009929:Organ Size; D010100:Oxygen / Q000633:toxicity*; D012640:Seizures / Q000139:chemically induced / Q000662:veterinary
D010100:Oxygen