Quantitative measurement of erythropoiesis in the dog

The quantitative measurement of erythropoiesis requires the simultaneous determination of total red cell volume, rate of production of red cells and the red cell life span. The total red cell volume was measured with autologous Cr 51 -labeled red cells, the rate of production of red cells from the rate of disappearance of radioiron from the plasma and uptake by red cells, the red cell life span with C 14 -labeled glycine and the apparent red cell survival T 1/2 with Cr 51 . The average total red cell volume of the dogs studied was 38.6 cc/kg; the plasma radioiron T 1/2 was 66 minutes; the red cell radio-iron uptake was 80%; the serum iron was 102 µg/100 cc, and the plasma volume calculated from the peripheral hematocrit and total red cell volume was 46 cc/kg, and from the extrapolation to t 0 of the radioiron disappearance was 48 cc/kg. From these figures the plasma iron turnover was calculated to be 0.63 mg/kg/day and the red cell iron renewal rate 1.26%/day. The average red cell life span was 108 days; the average apparent T 1/2 of Cr 51 red cell survival was 24.3 days; the average elution rate of Cr 51 was 1.77%/day.