Studies on Mammalian Red Cells 



83 



in the bone marrow and the haemoglobin synthesis proceeds in the 

 blood stream. 



We gave two hens the same dose of ^^N-labelled glycine. Hen I was 

 given intraperitoneal injections early in the regeneration and was killed 

 48 hours later (Fig. 1). At the time of killing the blood cells have thus 

 been under influence of labelled glycine during their growth period in 

 the bone marrow. Hen II was given labelled glycine 12 hours before 

 killing, during the period of maximal amount of immature cells in the 

 blood (Fig. 1). These blood cells thus have been under the isotope 

 influence only a short time during their haemoglobin synthesis. 



Table I shows some values of ^^N excess in the hsemin and globin 

 from the blood of the two hens. Hen I, which was given labelled 

 glycine during an early stage of regeneration, has a high incorporation of 



Table I 



Blood from Hen I and Hen II. Relationship between ^^N Excess in 

 THE Glycine (Chromatographically Isolated from the Globin) and in 



H^MiN (Crystallized) 



i^N in the glycine isolated from the globin and also fairly high incorpora- 

 tion in the haemin. The second hen, whose blood cells were under the 

 influence of labelled glycine only a short time during a period of intense 

 haemoglobin synthesis, shows high incorporation of ^^N in the haemin 

 but considerably lower incorporation in the globin. 



I think that a reasonable conclusion from this experiment might be 

 that during blood cell regeneration in these anaemic hens there is a 

 difference in time between the formation of the globin and the porphyrin 

 during haemoglobin synthesis. 



Neuberger: One wonders how far these experiments can be compared 

 with experiments done on mammalian red cells without a nucleus. You 

 might get quite a different time relationship of various processes in 

 nucleated cells compared with non-nucleated cells. The other compli- 

 cation is that an anaemia, probably a fairly severe anaemia, w^as pro- 

 duced and that is not strictly comparable to our experiments, in which 

 the haemoglobin content was normal. 



Wormall: I gather that Dr. Neuberger is anxious to find some other 

 label for the red cell, and that he wasn't quite happy about the labelling 

 of the cholesterol in comparison with the labelling of the haemoglobin. 

 I commend to his notice radioactive zinc, ^^Zn. Tupper, Watts and I 

 have shown in recent times that zinc goes into the red cell fairly quickly 

 and combines with a variety of compounds, though it doesn't enter very 



