Figure 3. Percent of the marrow space (mean ±SEM) occupied by hematopoietic precursors in intact control (I−R) and irradiated (I+R) mice estimated by visual inspection by a board certified veterinary clinical pathologist (LS) employing standard protocols.

Radiation caused marked hypocellularity of the hematopoietic components of the marrow by Day 3, with significant increases but still very low hematopoietic activity on Day 8 and marked but still incomplete recovery of hematopoietic activity with normal precursor maturation at Day 30. There were no changes over time in non-irradiated animals. Two-way ANOVA with Tukey's post-tests: * Irradiated mice had significantly lower cellularity than control mice of the same day, p<0.0001, † Cellularity of irradiated mice increased significantly from Day 3 through Day 30, p: 0.0292 – <0.0001.