Maintenance of normal platelet mass in anemic Belgrade rats and their response to iron.

The Belgrade (b/b) rat has severe hypochromic, microcytic anemia accompanied by mild thrombocytopenia and a 49 % reduction in megakaryocytes (MKs). We further characterized the b/b rat by examining the MK progenitors (MK colony-forming units, CFU-MK), MK ploidy, and platelet size to correlate them with the degree of megakaryocytopenia and thrombocytopenia. We simultaneously studied the granulocyte-macrophage (GM) progenitors (GM colony-forming units, CFU-GM). Secondly, because Fe treatment is effective in prolonging survival of b/b rats, we evaluated the effects of Fe therapy and the resultant partial correction of the severe anemia on the MK and GM progenitors and their progeny