Accession Number : AD0640734


Title :   A MODEL FOR POSTRADIATION STEM CELL KINETICS,


Corporate Author : ARMED FORCES RADIOBIOLOGY RESEARCH INST BETHESDA MD


Personal Author(s) : BAUM,S. J.


Report Date : JUL 1966


Pagination or Media Count : 16


Abstract : In polycythemic rats observed for 17 days postradiation (300 R, 250 KVP X-rays) it was noted that stem cell release diminished to 8 percent of the control values during the first 24 hours. This was followed by a rapid recovery from the 2nd to the 5th day. A second decrease was noted from the 6th to the 9th day and a third depression from the 9th to the 12th day. Thereafter, the oscillations diminished indicating a possible return toward the preradiation normal state. Similar recovery curves were observed in rats exposed to 200 rads X-ray or fission radiation. An attempt was made to correlate these findings with a kinetic model of erythropoiesis. It was suggested that the initial depression in stem cell release might be due to cellular destruction and inhibition of cellular release mechanisms. The oscillations of the recovery curves were ascribed to possible rate differences in cellular movements from one precursor compartment to the subsequent one, and to competitive stimulations for progenitor cells from related cellular systems of the hematopoietic system. (Author)


Descriptors :   *RADIATION EFFECTS, *HEMATOPOIETIC SYSTEM, RADIATION INJURIES, BLOOD DISEASES, RADIATION DOSAGE, RECOVERY, RATS.


Subject Categories : RADIOBIOLOGY


Distribution Statement : APPROVED FOR PUBLIC RELEASE