Table 4. Megakaryocyte number and myeloid: erythroid ratio in intact (I) and ovariectomized (OVX) mice receiving either 0 (−R) or 16 Gy radiation (+R) 30 days previously.

Hormone status	Radiation	Megakaryocytes					Myeloid∶Erythroid ratio
Intact	0	0	0	0	0	0	0	0	0	0	0
	16 Gy* ‡	−1	−1	−1	−1	0	+1	+1	+1	+2	+2
OVX	0	0	0	0	0	0	0	0	0	0	0
	16 Gy* † ‡	−2	−2	−2	−2	−3	+1	+1	+1	+1	+1

Semi-quantitative estimates performed by a board certified veterinary clinical pathologist (LS) according to standard protocols. Cells contain the data for individual mice (n = 5/group). Numerical scale: −4 severely decreased, −3 markedly decreased, −2 moderately decreased, −1 mildly decreased, +1 mildly increased, +2 moderately increased, +3 markedly increased, +4 severely increased, normal assigned a value of 0 for statistical calculations. Wilcoxon rank-sum test:

^*Radiation exposure significantly decreased megakaryocyte numbers compared with non-irradiated in both intact and OVX mice (p = 0.0450 and 0.0217, respectively), and

^†OVX exacerbated the decrease in megakaryocytes after radiation exposure (I+R vs. OVX+R, p = 0.0255).

^‡Myeloid:erythroid ratio was increased by irradiation in both intact and OVX mice (p = 0.0236 and 0.0182, respectively).