[Splenic hematopoiesis in an experimental model of hemolytic anemia]

The splenic hemopoiesis of rabbits, made anemic with acetylphenylhydrazine, and of control animals was investigated. Pieces of spleen of both groups were fixed in formalin and embedded in paraffin. Paraffin sections, cut 5-7 microns in thickness, were stained with hematoxylin-eosin, Giemsa, Perls' method for tissue iron (hemosiderin), and Perls-Chayen's method for iron stored in the hemoglobin. The erythroid line in the anemic rabbits, showed a marked increase of proerythroblasts and basophilic erythroblasts, while the poli and orthochromatic erythroblasts were less than their precursors. In contrast these cells were more than their precursors in control animals. There was no notable quantitative difference in the mature elements of this line in the anemic animals and in the controls. Megaloblasts and macroblasts were frequently observed in anemic spleens but they were practically absent in the controls. Regarding to other cell lineages, we noted in the anemic spleens many macrophages containing Perls and Perls-Chayen positive material and some megakaryocytes. Our results indicate that the APH-induced anemia stimulate the erythropoietic activity of the spleen in the rabbit, but the reversion of the amplification phase of the differentiation steps reveals that the erythropoietic process is ineffective. The presence of megalo- and macroblasts provide morphological evidence of dyserythropoiesis and the megakaryocytes suggest that under the anemia condition also the platelet regenerating process is stimulated.