The seeding efficiency of normal and hereditarily anemic (b/b) rat bone marrow colony forming units-spleen as determined in a "rat to mouse" assay.

Abstract

We demonstrated recently a decreased number, concentration and proliferative activity of colony forming units-spleen day 8 (CFU-Sd8) in the bone marrow of the hereditarily anemic Belgrade Laboratory (b/b) rat. The main consequence of the genetic defect in the b/b rat is impaired intracellular transport of iron resulting in altered hemopoietic stem and progenitor cell compartments. In this study, the seeding efficiency (f) for normal and b/b rat bone marrow CFU-Sd8 was determined in a "rat to mouse" CFU-S assay. There were no differences in f values for normal and b/b rat bone marrow CFU-Sd8, indicating that the severe anemia and consequent metabolic alterations did not affect f in the b/b rat. The calculation of CFU-Sd8 concentration per 10(5) normal rat bone marrow cells using f as a correction factor revealed a value similar to that found for populations of bone marrow cells defined by phenotypes Ox7+ (20%), Ox22-, W3/13dim, considered to be characteristic of CFU-S. The results revealed the usefulness of the "rat to mouse" assay for the determination of rat hemopoietic stem cells.