Comparison of life span of erythrocytes in some inbred strains of mouse using 14C-labelled glycine.

The erythrocyte life span in four inbred strains of mice--C57BL/10ScSnPh, B10.LP, BALB/c and CBA/JPh--was determined by means of erythrocyte labelling with 14C-glycine. Experimental data [decrease of 14C-activity of washed erythrocytes], corrected for blood loss, reincorporation of the label and delay in label incorporation during the initial period, were treated by a novel mathematical procedure based on the death probability function of the form: mu [t] = a + btlambda. The mean erythrocyte life span calculated using this function was, in the given sequence of strains, 42.1 +/- 0.6, 41.3 +/- 1.2, 39.3 +/- 0.9 and 38.6 +/- 0.6 days respectively. The rate of "random" destruction of erythrocytes was 1.20, 1.31, 0.70 and 0.63% of the total number of erythrocytes per day and a "mean potential" erthrocyte life span was found to be 58.9, 59.9, 46.2 and 44.5 days respectively. All the given parameters have similar numerical values in related strains and are apparently genetically conditioned. The erythrocyte life span determined simultaneously using DF32P labelling in the C57BL/10ScSnPh strain was 47.4 +/- 1.0 days. The implications of the results yielded by these two techniques is discussed.