Pluripotent and committed haemopoietic progenitor cells in rat peripheral blood

The assay system for determination of haemopoietic progenitors in peripheral blood of rats is essen tial for potential studies on mobilisation and transplantation of circulating progenitor cells in a rat experimental model. This paper demonstrates the possibility of detection and quantification of pluripotent progenitors (Colony Forming Units-Spleen day 8-CFU-Sd8) and committed progenitors (Colony Forming Units Granulocyte Macrophage-CFU-GM and Burst Forming Units-Erythroid-BFU-E) in peripheral blood of rats in a steady state. For determination of CFU-Sd8 the rat to mouse in vivo assay was used, and for committed progenitors in vitro assays on methylcellulose were employed. The CFU-Sd8 incidence ranged from 7.3 to 11.6/ml of rat blood, similar to that reported in literature for mice. The incidence of CFU-GM was found to be 59.7 ± 9.4/ml which is in the range of the literature data for mice, rabbits, dogs and humans. The incidence of BFU-E in rat peripheral blood was 4.3 ± 1/ml, which was relatively low, but could be also considered as comparable with some literature data for dogs and humans. The CFU-E were not detected by the technique used. These results confirmed the existence of circulatory blood pluripotent progenitors (CFU-Sd8) and committed (CFU-GM and BFU-E) progenitors in rat, as has been established for some other mammalian species.