Residual radiation effect in the murine hematopoietic stem cell compartment.
Stem cells surviving radiation injury may carry defects which contribute to long-term effects. The ratio of 125-iododeoxyuridine (IUdR) uptake into spleens of lethally irradiated recipient mice between day 3 and day 5 after cell transfusion revealed reduced proliferative ability (PF) of spleen seeding cells in parallel with reduced CFU-S content of donors throughout the study period of one year after 5 Gy gamma irradiation. Additional data aided in evaluating possible mechanisms of PF reduction. Within the range of the graft sizes used, PF was independent of the numbers of cells or CFU-S transfused. Radiation-induced increase in loss of label between days 3 and 5 and prolonged doubling time of proliferating cells indicated enhancement of cell maturation and increase in mitotic cycle time. Increased IUdR uptake per transfused CFU-S suggested extra divisions of transit cells due to insufficiency in the stem cell compartment. It is concluded that persisting defects in surviving stem cells interfere in a complex way with cell proliferation in the hemopoietic system.
D000818:Animals; D002455:Cell Division / Q000528:radiation effects; D003114:Colony-Forming Units Assay; D005260:Female; D005720:Gamma Rays; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000528:radiation effects*; D007065:Idoxuridine / Q000378:metabolism; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008815:Mice, Inbred Strains
D007065:Idoxuridine