Accession Number : AD0635086
Title : ERYTHROCYTE STEM CELL KINETICS IN THE POSTRADIATION RAT
Descriptive Note : Scientific rept.
Corporate Author : ARMED FORCES RADIOBIOLOGY RESEARCH INST BETHESDA MD
Personal Author(s) : BAUM, S J
Report Date : May 1966
Pagination or Media Count : 22
Abstract : In rats exposed to 300 R of 250 KVP X-rays, erythropoiesis as measured by 50 Fe uptake diminished greatly for 48 hours followed by a rapid recovery approaching near normal values approximately 6 days after radiation. IT HAS BEEN POSTULATED THAT THE RATE OF RECOVERY WAS PRIMARILY DUE TO ACCELERATED RELWASE OF NONINJURED STEM CELLS. The present experiment was designed to test this hypothesis. The polycythemic rat preparation was used since it permits the experimenter to control the release of erythrocyte stem cells. In polycythemic rats observed for 17 days postradiation (300 R of 250 KVP X-rays), stem cell release dimished 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. 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 inhibitions of cellular release mechanisms. The oscillations of the recovery curve 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.
Descriptors : *HEMATOPOIETIC SYSTEM , *RADIATION EFFECTS , IRON , PATHOLOGY
Subject Categories : Radiobiology
Distribution Statement : APPROVED FOR PUBLIC RELEASE