Foetal Haemoglobin and Rh. Antagonisms 



J. H. P. JONXIS 



The differences between foetal and later haemoglobin in human 

 beings make it probable that in foetal Hb the four parts from which 

 the Hb molecule {mol. weight 68,000) may be built up are connected 

 more firmly with each other than in later Hb. In most other 

 mammalia the forces which hold together the parts of the Hb 

 molecule are greater in the adult form. In adult human beings two 

 forms of Hb can be detected. The alkaline resistances of these two 

 forms are only slightly different. In cases of erythroblastosis 

 foetalis due to the Rh. antagonism the red blood corpuscles con- 

 taining foetal Hb are haemolyzed, the erythrocytes which already 

 contain later Hb being only slightly attacked. 



That there are differences between the haemoglobins of the newborn 

 and of adults was demonstrated for the first time in 1866 by E. Korber 1 . 

 In that year he published a paper on the differences in the resistance of 

 foetal and normal blood to alkalis and acids. Since then other 

 investigators 2 ' 3 ' 4 have repeated these experiments, using more or less 

 pure haemoglobin solutions instead of whole blood. 



Besides this difference there are others : various crystal forms, 

 differences in solubility and iso-electric point, differences in amounts 

 of amino-acids, absorption spectra, dissociation curves, and different 

 behaviour in monomolecular layers. 



Figure 1. The influence of the 



denaturation of oxyhaemoglobin on 



the extinction at a wavelength of 



650 m/x. 



60 120 180 240 



Concentration Hb mo/IOOml 



One of the most simple methods of distinguishing haemoglobins is 

 the determination of differences in denaturation rate in buffer solutions 

 of pH 12-7. In the course of this denaturation the red colour of 

 oxyhaemoglobin changes into the brown of alkaline-globin-haemo- 



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