Effect of a stimulating factor on granulopoiesis in sublethally irradiated mice.

Sublethally irradiated mice were used as a model for an in vivo study of the effect of the stimulating factor present in rat leukophoretic serum (LS). LS was obtained from rats with inflammation induced by polyvinylpyrrolidone. Irradiated mice were injected i.v. with 0.2 ml LS, normal rat serum or Parker 199 medium, respectively. Animals were sacrificed 24, 48 and 72 h later. The obtained data indicated that LS stimulated the proliferation of granulocytic cells in the period observed.