KINETICS OF PLURIPOTENT HEMATOPOIETIC PRECURSORS INVITRO AFTER ERYTHROPOIETIC STIMULATION OR SUPPRESSION

Abstract

The kinetics of [mouse] pluripotent hemopoietic precursors (CFUmix) in vitro was studied during erythropoietic stimulation and suppression. Erythropoiesis was stimulated by the s.c. injection of 60 mg/kg phenylhydrazine hydrochloride on days 0, 1 and 3. Erythropoiesis was suppressed by transfusion of 1 ml of the packed red cells on 3 consecutive days. After erythropoietic stimulation, CFUmix were decreased in the femur and increased in the spleen. In contrast, the CFUmix were increased in the femur and the spleen after suppression of erythropoiesis. The kinetic behavior of CUmix were similar to those of CFUs [pluripotent hemopoietic stem cells] reported previously. The behavior of CFUmix during erythropoietic stimulation and suppression revealed another biologic similarity between CFUmix and CFUs, in addition to the similarity of proliferative state and sedimentation velocity.