RECOVERY FROM RADIATION INJURY IN THE HAMSTER AS EVALUATED BY THE SPLIT-DOSE TECHNIQUE.
Abstract
The split-dose technique was used to determine the pattern of recovery from radiation injury in the Syrian hamster (Mesocricetus auratus). Exposure of the animals to 1 Mvp X-rays resulted in a LD50/30 of 941 R (95% confidence interval: 917-967 R). Recovery, defined as a return to normal radiosensitivity after a sublethal exposure, was found to be non-exponential; in fact, a marked transient increase in radiosensitivity was observed during the second week. After exposure to 2/3 LD50/30, relatively little recovery was observed on the 3rd day after the conditioning exposure; 94% of the initial injury remained. Between the 3rd and 7th day the hamster recovered at a rapid rate; only 26% of the initial injury remained on day 7. These periods of recovery were followed by a regression of the animals to a more radiosensitive state; 76% of the initial injury was present on day 11. After this time, the animals returned toward more nearly normal radiosensitivity; 20% of the initial injury remained at day 20. These findings are a marked deviation from the exponential recovery pattern usually reported for other rodents. Hematological studies indicate that the extent of recovery, in terms of split-dose radiosensitivity, is not correlated with the number of circulating erythrocytes, thrombocytes, granulocytes, or mononuclear cells. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 20, 1966
- Accession Number
- AD0647224
Entities
People
- E. J. Ainsworth
- G. F. Leong
- M. L. Albright
- R. J. Holloway
- S. J. Baum
Organizations
- Naval Radiological Defense Laboratory