Chapter IV 

 MAST CELLS IN PATHOLOGICAL CONDITIONS 



TO study the presence and significance of mast cells in pathological 

 states is again to acknowledge our debt to the pioneer observations of 

 Ehrlich (1878) who, it will be remembered, chose the name ' Mastzellen ' 

 following his observation that the cells are more numerous where the local 

 nutrition of the connective tissues appears to be enhanced.* Ehrlich (1879) 

 describes two situations where connective tissue may be overnourished, in 

 chronic inflammation and the environs of tumours. Here, he infers, there 

 exists a lymph stasis, a damming up of tissue fluid rich in nutriment, whereby 

 certain fixed connective tissue cells are stimulated to become mobile, to multiply 

 and to convert some of the abundant extracellular material into specific intra- 

 cellular granules — a process of 'mastung' or fattening (the German root is 

 still preserved in such English words as beech "mast 1 and 'mastication'). 

 According to Ehrlich (1879) the mast cells are 'indices of the nutritional state 

 of the connective tissue', increasing during periods of hypernutrition, diminish- 

 ing during periods of relative starvation. And it must be admitted that all the 

 research work of the past seventy-five years has failed to displace entirely 

 this original hypothesis of the function of the mast cell in relation to the 

 connective tissues. 



Mast cells and inflammation 



Ehrlich was careful to point out that a local increase in the mast cell 

 population occurs only in chronic inflammation. Mast cells are thus common 

 in chronic paronychia (Baumer, 1896), in chronic gingivitis (Todoro, 1938) 

 and in other situations where fresh connective tissue is being laid down 

 (Staemmler, 1921), even though the normal organ might originally be poor 

 in connective tissue and lacking in mast cells, as in brain (Neumann, 1885; 

 Baeckeland, 1950), thyroid (Blomquist, 1956) and kidney (Baar and Bickel, 

 1952). In comparing normal and diseased organs Janes and McDonald (1948) 

 regularly observed an increase in the number of mast cells in chronic inflam- 

 matory conditions of joints, appendix, gall bladder, breast, uterus, prostate and 

 other organs and tissues in which there is fibrosis. Mast cells are thus commonly 

 seen in the granulomatous lesions of syphilis, tuberculosis (Harris, 1900) and 

 regional ileitis (Trincao, 1953). Increased numbers of mast cells have also been 



* Ehrich's 'Mastzellen' are variously described by later investigators as 'cellules isoplastiques \ 

 ' cellules a l'engrais ', ' mastocytes ', 'cellulas cebadas', etc. Among modern workers, Arvy (\955d) 

 still prefers the term 'labrocyte', once favoured by Michels (cf. Michels, 1938, footnote p. 251, and 

 discussion to Arvy, 19556, pp. 222-223). 



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