Mathematical theory of the determination of the life span of red blood cells by isotopic method.

A general discussion on the isotopic determination of the life span of the red blood cells has been given. By appropriate assumptions. an attempt has been made to analyze the isotopic curve i. e. the total number of isotopic atoms in the circulating red blood cells vs. time. Making use of Laplace transform of G(t), the number of isotopic atoms in the circulating red blood cells at time t , we have found that I;;" G(t) dt/Co(equation(33)) gives the mean life span of the red blood cells, where Co is the total number of the isotopes which are introduced into the circulating red blood cells. From this relation, We obtained a new simple me· thod to determine Hie life span of the red blood cells. The life span of red blood cells obtained by this method gives good agreement with the previous values given by the other people. While analyzing the tale part of the isotopic curves, we have known that there is a portion of Nt5s of glycine which is utilized slowly in the formation of heme after passing through the other tIssues. Assuming the atom% excess versus time curve is composed of 2 terms. e.g.. normal life span term and random destruction term, estimation of the ratio of number of red blood cells of normal life span to random destruction was made. Equation (32) gives this relation and in figures 4 and 5 data cited from other sources and calculated are plotted