THE ERYTHROPOIETIC ACTION OF GERMANIUM DIOXIDE : II. THE SOURCE OF THE ERYTHROCYTHEMIA PRODUCED BY GERMANIUM DIOXIDE IN THE ALBINO RAT.

A histological comparison of the liver, spleen, bone marrow, circulating young erythrocytes, and differential count in mature male and female albino rats receiving germanium dioxide with their litter controls not receiving this compound was made. It was found that the livers of the test animals in most cases showed a condition of capillary dilatation and that more erythrocytes were in these capillaries than were in those of the controls. There was no evidence of any red cell formation by the liver. The spleens of the test rats gave the impression of being slightly more congested and of having a slightly more dense concentration of cells in the Malpighian corpuscles than those of the controls. There was no evidence of an increased red cell destruction nor was there any evidence of splenic erythropoiesis. In the bone marrow of the rats which had received the germanium dioxide injections there was evidence of a marked stimulation in formation of nucleated erythrocytes, in that many more of these cells were found here than in the marrow sections of the controls. The circulating blood of the test rats contained more young red cells as demonstrated by the increased number of erythrocytes taking the polychromatic stain than did the blood of the controls. No noteworthy differences in the values for the various types of white cells in the circulation determined by the differential count could be found between the two groups. Using, then, as an acceptable criterion of erythropoiesis an increase in the number of erythrocytes in the circulation which is accompanied by an increase in the number of young red cells, and an increased number of nucleated erythrocytes in the bone marrow, we consider ourselves justified in concluding that germanium dioxide is a potent erythropoietic agent and the source of the erythrocythemia produced by this compound is the increased production of red cell precursors by the bone marrow stimulated to increased activity by the compound used.