THE MAST CELLS 



Irrespective of the precise nature of the pathological process, the present 

 material settles beyond all reasonable doubt the view that tissue mast cells are 

 extraordinarily rich in histamine and that, in most tissues at least, the bulk of 

 the extractable histamine can be accounted for on this basis. It is thus of great 

 interest that Graham and her associates (1952; 1955) find that much of the 

 histamine in blood, especially in man, is likewise located in the basophils, or 

 blood mast cells, though this is not necessarily true for all species (Code and 

 Mitchell, 1957). Tissue mast cells are rich in histamine in all higher organisms 

 so far examined. 



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