ABSTRACT
Studies of the survival of circulating autologous chromium-51-labeled red cells in the rhesus monkey conducted along with the independent study of DF32P-labeled red cells in the monkeys discussed earlier (Kreier et al. 1970) have led these authors to conclude that the life span of the red cells of Macaca mulatta as derived per sodium chromate labeling is 86-105 days. The mean elution rate of the chromium from the tagged cells was 3.15% per day. The half-life of the circulating 51Cr-labeled erythrocytes extrapolated from the published graph was ~17-18 days. The technique for 51Cr labeling of erythrocytes obtained from the circulating blood that was utilized by Kreier et al. included the following steps. A sample of blood was obtained from a given rhesus monkey; the red cells were incubated with radioactive sodium chromate and reinjected intravenously into the donor. The survival of the labeled autologous red cells was monitored for 110 days with the sample taken at 24 hours considered as the 100% level. The radioactivity of the tagged circulating red cells was determined by lysing collected erythrocytes and assaying for 51Cr in the resultant solution of hemoglobin by gamma spectrometry with a well-type, solid scintillation detector.
