Life-Span of Red and White Blood Corpuscles of the Hen

Abstract

IN a former communication¹, a method of determining the life-cycle of nucleated erythrocytes was described. The method is based on the fact that radiophosphorus incorporated into desoxyribose-nucleic acid molecules during the formation of the red corpuscles in the marrow of the hen remains in the erythrocytes throughout their life-time. If labelled sodium phosphate is administered repeatedly to a hen with the aim of keeping the plasma activity at a constant level, the specific activity of the desoxyribosenucleic acid phosphorus extracted from the erythrocytes is found to increase with time according to a linear curve and to reach the level of the specific activity of the inorganic phosphorus of the blood plasma after the lapse of 33 days. Thus, after that date, we find only such red corpuscles in the circulation as were formed during the experiment. As, according to these experiments, about five days elapse before the labelled corpuscles are released into the circulation, the life-span of the red corpuscles works out to be 33-5 = 28 days.