Hematologic Findings in the Total Body X-irradiated Hamster

Hematologic determinations were made on cardiac blood from normal hamsters and from four groups of hamsters at daily intervals after total body irradiation with 600 r, 1000 r, 1200 r and 1500 r. Pancytopenia, lowered hematocrit, and decreased hemoglobin occurred. The clotting times were extended in the 1200 r and 1500 r groups, and this defect was correlated temporally with thrombocytopenia and disrupted mast cells. The sedimentation rates were increased terminally in the lethally-irradiated hamsters. The significance of these findings and the relationships to visual observations on the peripheral circulation such as leukocytic pavements on capillary and venular endothelium, platelet thromboembolic phenomena, erythrocytic extravasations, and circulating red cell aggregates are discussed.