Physiological response to experimentally induced anemia in rats: a comparative study.

To induce anemia experimentally in rats to provide a hematocrit of 30 to 35% and provide data about the physiologic response to anemia during induction and after it is established, two methods were selected: the application of repetitive doses of phenylhydrazine and bleeding. Blood sample collection was carried out at various times, and hematologic profiles and osmotic resistance were evaluated. The morphologic features of cells and distinct organs also were examined. Results indicated similar decrease of hematocrit and hemoglobin concentration for the two experimental groups, although the reticulocyte response was higher in rats treated with phenylhydrazine, where the presence of young erythrocyte populations was linked to increases in osmotic resistance and glucose utilization. 2,3-Diphosphoglycerate was induced only during the recovery phase of the study and corresponded to a gradual response to hypoxia. Histologically, marked erythroid hyperplasia was found in the bone marrow, and extramedullary hematopoiesis was seen in the spleen and liver.