In vitro growth of rat bone marrow BFU-E.

Pokeweed mitogen-stimulated rat spleen cells were identified as a reliable source of rat burst-promoting activity (PBA), which permitted development of a reproducible assay for rat bone marrow erythroid burst-forming units (BFU-E). Optimum BPA dose, assay time, cell dose, and erythropoietin requirements for rat BFU-E were identified. A serum-free assay and a method for stimulating endogenous bone marrow BPA were developed. Identification of sources of rat BPA and characterization of the rat BFU-E assay makes this species more useful for hematopoietic studies. The similarity of rat BFU-E to human and mouse BFU-E strengthens the validity of rat models for erythropoiesis.