RADIOBIOLOGICAL EXPERIMENTS IN THE HIBERNATING DORMOUSE

Journal Article · Sun Jan 01 04:00:00 EST 1961 · Chemotherapia (Switzerland) Changed to Chemotherapy (Basel)

DOI:https://doi.org/10.1159/000219545· OSTI ID:4743869

Kuenkel, H A

The effect of x radiation on dormice was investigated in both the hibernating and waking state. In waking animals given 700-r 200-kv irradiation, the 30-day mortality was approximates 37%. However, after irradiation of hibernating animals with the same dose, none of the animals died in the subsequert 21-day period of continuous hibernatton. No outward evidence of radiation effects was noted in the hibernating dormouse, but if they were awakened by warming to 38 deg , the effects of radiation appeared. When awakened 21 days after irradiation, the mortality rate 30 days later (51 days after irradiation) reached 55%. Thus, the awakened animal began to die about 25 days after irradiation, at which time no further deaths occurred in the animals irradiated in the waking state. When groups of waking dormice were given whole- body doses of 1200 to 12,000 r, survival time fell as the dose increased up to approximates 3000 r at which dose it leveled off at 4.2 days. In contrast, in irradiated hibernating dormice not awakened after irradiation, survival time fell sharply from 39 days at 1000 r, then leveled off at 23 days at 8000 r, and fell sharply again to reach 14 days at 10,000 r. The survival curves, showed that the limiting 4.2-day phenomenon does not occur in hibernating animals In waking animals irradiated with 700 r, 10-min prior injection of 500 mg/kg cysteine intraperitoneally was fully radioprotective, no animals dying within 30 days in comparison with 37% mortality in controls. No protection was afforded, however, if the same dose of cysteine was given 3 min after irradiation. Cysteine was also effective when given 15 min before irradiation of hibernating dormice; no animals died during the subsequent 21-day hibernatton period and an additional 30- day waking period. Even when cysteine was injected 21 days after irradiation and 1 hr before awakening it was markedly effective as a radioprotectant; the mortality was only 5% in these animals in contrast to 55% in animals not given cysteine. Histologic studies were also conducted in bone marrow and other organs of irradiated dormice to detect differences in radiation effects in the waking and hibernating states. Tissue and cell damage was present in irradiated hibernating animals but its appearance was delayed. Liver adenosinetriphosphate (ATP) content was more than twice as great in hibernating than in waking animals, and within 4 days of rewarming it fell to normal. It was concluded that in the hibernating animal, radiation induces the usual primary reactions, such as free radical formation, but that the concomitant secondary chemical reactions are inhibited urtil the homoiothermic state is re-established, Cysteine may manifest its radioprotective action by blocking the later reactions. (P.C.H.)

• Research Organization: Universitats-Frauenklinik Hamburg-Eppendorf, Ger.
• NSA Number: NSA-17-007827
• OSTI ID: 4743869
• Journal Information: Chemotherapia (Switzerland) Changed to Chemotherapy (Basel), Journal Name: Chemotherapia (Switzerland) Changed to Chemotherapy (Basel) Journal Issue: 3 Vol. Vol: 3; ISSN CMTRA
• Country of Publication: Country unknown/Code not available
• Language: German

Related Subjects

ANIMALS
BIOCHEMISTRY
BIOLOGY AND MEDICINE
BONE MARROW
CHEMICAL REACTIONS
CYSTEINE
FREE RADICALS
HIBERNATION
LIFETIME
RADIATION DOSES
RADIATION EFFECTS
RADIATION INJURIES
RADIATION PROTECTION
RADIOBIOLOGY
TEMPERATURE
TISSUES
X RADIATION