Hemopoietic stem cell mobilization in mice

In mice hemopoietic stem cells and progenitor cells are almost totally confined to the bone marrow and spleen. Only small numbers can be detected in the peripheral blood. Relatively little is known about the mechanism(s) modulating the circulation and mobilization of stem cells. At present their function and ultimate fate are unknown. Mobilization of hemopoietic stem cells in mice has been achieved by injection of a variety of substances, the most well known being LPS. For some substances, including endotoxin, the transient increase in blood CFU-s immediately following injection (early mobilization) is followed by a second one some days later (delayed mobilization). The purpose of the investigations presented in this thesis was to get insight into the mechanism(s) underlying both early and delayed mobilization of hemopoietic stem cells by LPS and other agents. Additionally, the changes in splenic hemopoiesis seen after administration of LPS have been subject of investigation