THE MAST CELLS 



Results 



It will be seen from Table II that there is indeed a striking correspondence 

 between the histamine values on the one hand and the mast-cell, or heparin, 

 contents as indicated by Jorpes' data, on the other. This at once provides 

 powerful support for the hypothesis that tissue mast cells are exceptionally 

 rich in histamine. Much of the remainder of this book is concerned with the 

 description of the further experimental procedures which were devised to test 

 and consolidate this basic premise. 



Table II 



Histamine content {\xg.jg.) of tissues compared with heparin 



content (mg. standard heparinjkg.) and the relative mast-cell 



content 



* Data of Jorpes (1946) 



Ox liver capsule 



When these preliminary results were reported (Riley and West, J. Physiol., 

 117: 72P, 1952) the histamine value for ox liver capsule had been obtained from 

 specimens which comprised the outermost rind of the liver, a layer of tissue 

 approximately -5 cm. thick containing both capsule and parenchyma. However, 

 paraffin sections show beyond doubt that the mast cells are located almost 

 exclusively in the serous and immediately subserous tissue of the true capsule 

 (Fig. 5). Attempts were therefore made to obtain purer samples of the capsule 

 and to compare their mast-cell and histamine contents. 



It was eventually found that the key to the successful removal of the capsule 

 of ox liver is to strip the capsule off the intact liver as soon as possible after 

 its removal from the animal. An incision is made through the capsule around 

 the edge of the dome; and once the process of stripping has been started it is 

 then easy to peel off the entire capsule, the remainder of the organ (which weighs 

 up to 30 lbs.) acting as a counter- weight. The thin film of parenchyma which 

 still adheres to the under surface can be removed by spreading the capsule, 

 serous side down, on a sheet of plate glass and scraping the under surface 

 vigorously with a razor blade. The final product is a tough, semi-transparent 



72 



