Red Blood Cell Life Span Using DFP³² as a Cohort Label

In the dog, the erythrocyte uptake of DFP³² was found to be dependent upon the dose of administered DFP³². Effective blocking of red cell uptake of isotopically-labeled DFP was achieved by prior administration of unlabeled DFP. By allowing a time interval between the administration of DFP and DFP³² the cohort of red cells synthesized in that interval could be labeled with DFP³². The cohort of erythrocytes synthesized in response to acute blood loss were so labeled and were found to have a shortened life span with a pattern of random destruction.