title: The effects of repeated bleedings on bone marrow and blood morphology in adult laboratory rats.
abstract: There were slight and rapidly disappearing changes in the bone marrow and blood morphology of laboratory rats after repeated bleedings on consecutive days, except marked increases in the counts of circulating reticulocytes. However, the significantly elevated reticulocyte count was not accompanied by the similar increase in the count of marrow erythroid nucleated cells. Marked increments could be found in the counts of splenic erythroid nucleated cells and, therefore, it is possible for rat circulating reticulocytes to originate following repeated bleedings from the spleen. The validity of investigations of bone marrow and blood morphology for detecting haemorrhage is discussed with a view to preclinical safety drug evaluations performed on adult laboratory rats.
mesh_terms: D000367:Age Factors; D000818:Animals; D001854:Bone Marrow Cells; D006400:Hematocrit; D006470:Hemorrhage / Q000097:blood / Q000150:complications; D008297:Male; D009504:Neutrophils / Q000032:analysis; D051381:Rats; D011919:Rats, Inbred Strains; D012156:Reticulocytes / Q000032:analysis