Accession Number : AD0651879

Title :   ALTERED RECUPERATIVE POTENTIAL IN PREVIOUSLY IRRADIATED MICE,

Corporate Author : NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF

Personal Author(s) : Ainsworth,E. J. ; Larsen,Rex M.

Report Date : 03 APR 1967

Pagination or Media Count : 25

Abstract : Earlier studies have shown a non-recuperable component of radiation injury in rodents. This component is manifested by a small increase in radiosensitivity and as incomplete recovery of the hematopoietic system. The present studies were designed to evaluate the influence of previous sublethal irradiation, and perhaps non-recuperable lesions, on the ability of LAF 1 male mice to recuperate from X-radiation injury. Recuperation from radiation injury was studied using the split-dose method. Mice were given an initial exposure to 450 R of X-radiation from which they were allowed to recuperate. At 14 or 30 days after the initial exposure, the LD50's of the animals had returned to normal. When recuperation potential was measured at 14 days following the initial exposure, a significant delay in recuperation was observed. Thus, the return to a normal LD50 does not predict complete restoration of recuperative capacity. The delay in recuperation observed at 14 days was not present at 30 days after the initial exposure. This indicates that the radiation lesion which influences recuperation is not a persistent lesion. These findings have bearing on the concept of equivalent residual dose (ERD) which is used to predict radiation lethally in multiple exposure situations involving humans. (Author)

Descriptors :   (*RADIATION INJURIES, RECOVERY), X RAYS, RADIATION DOSAGE, SUBLETHAL DOSAGE, MICE

Subject Categories : Radiobiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE