Inter and intraspecies genetic differences in survival to an acute carbon monoxide challenge in mice, rats, guinea-pigs, quails and chickens.

1. Groups of small laboratory vertebrates, of both sexes, have been submitted to an acute carbon monoxide challenge, close to a LD50. 2. An interspecific classification, from low to high CO sensitivity, gives: guinea-pigs-mice-chicks-rats-quails. 3. Interstrain statistical differences were observed in all species, with the exception of guinea-pigs. Furthermore, among two selected genotypes of Japanese quails, one was resistant to acute nitrogen hypoxia and to carbon monoxide intoxication and the other sensitive to both these types of hypoxia. 4. Interspecific comparisons show similarities of genetic differences to acute CO intoxication and acute nitrogen normobaric hypoxia.