Insulin-driven erythropoiesis may underlie impairment of erythrocyte deformability in hyperinsulinaemic, hyperglycaemic ob/ob-mice.

The circulating erythrocytes in hyperglycaemic and hyperinsulinaemic obese (ob/ob) mice are enlarged with a decreased erythrocyte filtrability and an abnormally low resistance to osmotic stress. These changes probably reflect aberrations of erythropoiesis, as evidenced by endhanced staining for iron in the bone marrow, reticulocytosis, and increased erythrocyte volume fraction. Mature erythrocytes, reticulocytes, and late-phase basophilic erythroblasts were found to have larger diameters than their counterparts in control mice while myelopoiesis appeared to be unaffected. The average erythrocyte also displayed an increased cell volume and a decreased haemoglobin concentration. It is suggested that the stimulation of the erythroid cell line in ob/ob-mice might be a consequence of the hereditary hyperinsulinaemia.