Effect of low-dose whole-body irradiation on granulopoietic progenitor cell subpopulations: implications for CFUc release.
The reaction of the granulopoietic system to whole body irradiation with 0.80 and 1.60 Gy was studied in dogs by means of colony formation assays in combination with velocity sedimentation and tritiated thymidine cytocidal techniques. Depression of circulating CFUc was associated with a marked shift in the size distribution of granulopoietic progenitors in the bone marrow. This effect lasted much longer in those animals receiving the lower X-ray dose. We conclude that circulating CFUc are not a random proportion of the bone marrow but a subpopulation of cells which are smaller in size. These cells are in an equilibrium with the larger marrow CFUc, which is very sensitive to perturbations.
D000818:Animals; D001853:Bone Marrow / Q000528:radiation effects; D001854:Bone Marrow Cells; D002453:Cell Cycle; D002499:Centrifugation, Density Gradient; D003114:Colony-Forming Units Assay; D004285:Dogs; D006098:Granulocytes / Q000528:radiation effects*; D006410:Hematopoiesis / Q000528:radiation effects*; D006412:Hematopoietic Stem Cells / Q000528:radiation effects*; D007399:Interphase; D008297:Male; D011829:Radiation Dosage