CALCIUM AND IONOPHORE A-23187 AS INITIATORS OF DNA REPLICATION IN THE PLURIPOTENT HAEMOPOIETIC STEM CELL

The proliferation rate of the haemopoietic stem cells of the mouse bone marrow can be stimulated by an increase in calcium influx. This key event may be brought about by raising the external calcium concentration or, at lower calcium levels, by use of A-23187 as calcium carrier, within definite dose ranges depending on the Mg²⁺: Ca²⁺ molar ratio in the incubation medium. The hypothesis is postulated of an accelerated influx of Ca⁺ as the possible common mediator of the effects of the various types of agents known to control the CFU cell cycle.