[A mouse model of myelofibrosis induced by high dose of recombinant human erythropoietin].

Tn order to set up a mouse model of myelofibrosis (MF) induced with high dose recombinant human erythropoietin (rhEPO). 60 mice were collected and divided into EPO and control groups, the former was injected with rhEPO and the latter with normal saline intraperitoneally. 5 mice from each group were executed on day 6, 30, 60, 90, 120 and 150 respectively. Their WBC count, Hb level, MCV, RDW and platelet amount were measured by automatic blood cell analyzer; CD34(+) cell ratio in bone marrow were analyzed by flow cytometry; liver and spleen coefficients were measured; pathological changes of liver, spleen, femur were observed by HE staining and reticular fibers staining; cortex thickness, femoral canal diameter and lumbar spine density were determined by computerized tomography (CT). The results indicated that as compared with normal control group in EPO induced group, WBC count was increased slightly in whole period, but without statistic significance (p > 0.05), Hb level and RDW increased at day 6 and 30 significantly (p < 0.05), MCV increased at day 6 significantly (p < 0.05), but platelet amount decreased significantly at all time points (p < 0.05). Most mice in EPO-induced group had hepatomegalia and their liver and spleen coefficient increased significantly at day 60 (p < 0.05), while most mice had splenomegaly and its coefficient was increased significantly at all time-points (p < 0.05). CD43(+) cell ratio of EPO group increased significantly in whole period (p < 0.05). CT scanning displayed femoral cortical thickening, medulla canal narrowing and lumbar spine density increasing at day 150, meanwhile, HE staining and reticular fiber staining showed the fatty degeneration or vacuolization in liver, splenomegaly with megakaryocytic proliferation, femur bone marrow fibrosis and osteosclerosis. It is concluded that the mouse induced by high dose of rhEPO displays the myelofibrosis associated with splenic extramedullary hemopoiesis, and this study is useful to establish a practical MF model, and to explore its pathological mechanism.