Granulocytic Recovery in the Polycythemic Dog Treated with Endotoxin Postirradiation

This experiment was designed to test the hypothesis that, in hypertransfused dogs with suppressed erythropoiesis, endotoxin-induced myelopoietic stimulation 24 hr after irradiation would enhance leukocytic recovery. The treatment combination of transfusion polycythemia and endotoxin was compared to a control group receiving no therapy and to the results obtained from groups of dogs receiving each treatment alone. The radiation exposure was 150 rads of total-body x-rays. An accentuated abortive rise in the group receiving the combined treatment, accelerated recovery in both groups receiving endotoxin, and impaired leukocytic recovery in the polycythemic animals were observed. Accentuated depression of platelets and inverse correlation of platelet levels with splenic enlargement were observed in the animals receiving transfusion therapy regardless of whether they received endotoxin. It is felt that the data support the concept of interdependence between the various cell lines of hematopoiesis in an experimental model not previously described.