RECOVERY FROM RADIATION INJURY IN DOGS AS EVALUATED BY THE SPLIT-DOSE TECHNIQUE,
Abstract
The split-dose technique was used to evaluate recovery from radiation injury in dogs given an initial conditioning exposure to 217 R, which is approximately 2/3 of the LD50. Based on LD50's determined at 1, 3, 7, 14, and 20 days after the conditioning exposure, recovery is rapid with 50% recovery occurring by about 3 days. Because of relatively large 95% confidence intervals, the recovery rate per se is difficult to establish. An exponential curve with a recovery half-time of 3.1 days may be an acceptable fit to the data. However, between 3 and 20 days the animals' radiosensitivity appeared to change linearily at a rate of approximately 8.5 R/day. At 20 days approximately 40 R of radioresistance was detected, but this was not statistically significant. The numbers of circulating leucocytes were followed for several months after exposure to 150 R or 217 R. The leucocyte counts return to only 70-80% of the pre-irradiation values by approximately 4 months. The data are discussed in terms of the proposed correlation between recovery from radiation injury and basal metabolic rate or changes in the number of circulating leukocytes. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 30, 1965
- Accession Number
- AD0628791
Entities
People
- E. John Ainsworth
- George F. Leong
Organizations
- Naval Radiological Defense Laboratory