Influence of hypothermia on the survival of mice after large doses of x-radiation.

Abstract

IT is known that hypothermia applied after irradiation prolongs the survival of frogs1,2 and hibernating animals3, and slows down destructive processes in the haematopoietic tissue and blood3,4. In our previous work we showed that prolonged hypothermia at 22–25° C., lasting 6–48 hr., after irradiation also slows down destructive changes in the blood, spleen and bone marrow5,6. After the ending of hypothermia and reaching the normal body temperature these changes, however, develop even more intensely than in controls subjected to irradiation only and the mean survival-time is shorter. After doses up to 15,000 r. animals survive for more than 3 days after irradiation7 and do not tolerate such prolonged hypothermia. Therefore investigations of the survival-time after irradiation in homoiothermic animals under hypothermia can be carried out only after large doses of irradiation where the control animals die a few hours following irradiation, which is a well-tolerated duration of hypothermia.