Blood Group Substances 177 



teins. The establishment of the end group character of sialic acid 

 in submaxillary mucin has been mentioned above. Similar work 

 on the blood group substances with enzymes from Trichomonas 

 foetus and CI. welchii lead to release of fucose from H substance, 

 oc-galactose from B substance and both fucose and ^-galactose 

 from Le a substance. 



The concentration of blood group substance in saliva is com- 



Fig. 9.3. Human submaxillary gland from a subject of erythrocyte Group A. 

 Stained with anti A-fluorescein conjugate by Coon's technique. Note the high concentration 

 of A substance in the mucous cells and absence from serous cells or ducts. (Glynn and 

 Holboron, 1959.) 



monly of the order of 10-20 mg/1. It is therefore only a relatively 

 minor constituent of the total protein in saliva. In man very little 

 activity is found in extracts of parotid gland (Hartmann, 1 941) as 

 compared to submaxillary and the A substance cannot be detected 

 in parotid saliva (Burgen, unpublished). Glynn and Holborow 

 (1959) have studied the distribution of blood group substance in 

 the human saliva glands using Coon's fluorescent antibody tech- 

 nique and found strong staining specifically in the mucous cells of 

 the submaxillary gland with no staining in the duct cells (Fig. 9.3). 



P.S.G. — N 



