STUDIES ON MAMMALIAN RED CELLS 



A. NEUBERGER 



The Life Span of the Mammalian Red Cell 



Observations in Man 



In man several methods have been successfully used to 

 determine the life span of the red cell. With all these methods 

 the persistence of a particular component in the circulating 

 red cells over a period of time is determined and in order to 

 do this, the substance under investigation has to be labelled 

 and its concentration must be measurable by a physical, 

 chemical or biological method. If, as is the case, different 

 labelled components are used, it cannot be an a priori assump- 

 tion that the results obtained by the various methods will 

 necessarily be identical. In the technique originally devised 

 by Ashby (1919) group O cells are transfused into recipients 

 belonging to groups A or B and the persistence of cells lack- 

 ing A or B antigens is determined by agglutination. The 

 assumption is made that the transfused group O cells have 

 the same life expectation in the circulation of the recipient 

 as they would have had in their original environment, i.e. 

 in the body of the donor. It is also assumed that the agglut- 

 inogen is not detached before the cells die nor re-utilized in 

 the construction of a new cell. This method of biological 

 labelling has, so far as we are aware, only been applied to man. 



The other methods to be discussed use the persistence of a 

 label present in the haemoglobin molecule to estimate the life 

 span. Jope (1946) measured the rate of disappearance of 

 sulphgemoglobin from the blood of subjects who had been in 

 contact with trinitrotoluene immediately before the beginning 

 of the experiment. It is assumed that the cell thus chemically 

 labelled has the same life expectation as the normal red cell. 



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