THE MAST CELLS 



observed from Table XIII that the histamine values of biopsy specimens taken 

 at intervals during pregnancy also declined, only to rise again after the birth 

 of the calf. This immediately brings to mind the striking rise in activity of the 

 enzyme, histaminase, in the blood of women during pregnancy. However, 

 no comparable fluctuation is believed to take place in the blood histaminase 

 of cattle (Kolb, 1956). Presumably, therefore, either the association here is 

 fortuitous or some other factor in pregnancy is responsible. It is hoped that 

 material may become available during another pregnancy and so clarify the 

 situation. Histological examination at each stage showed good correspondence 

 with the results of the pharmacological assays, the majority of the mast cells 

 becoming less well granulated as pregnancy progressed. 



Table XIII 



Histamine and heparin values in multiple mast-cell tumours in a cow. Note 

 the fall in the histamine content during pregnancy. [C= calved] 



Other investigations on this case included cytological blood examination, 

 tissue culture and the attempted autotransplantation of tumour material. 

 Briefly the results were as follows. No changes were detected either in the 

 cellular composition of the blood or in its clotting time throughout the period 

 of observation ; indeed, only three blood basophils were encountered among the 

 1,400 white cells which were examined. 



Dr. J. D. B. MacDougall who had previously explanted material from a dog 

 tumour also succeeded in growing bovine mast cells in tissue culture from a 

 fragment of a biopsy specimen taken in December 1954 and reported his 

 findings at the International Congress of Anatomy in Paris in July 1955. 

 However, no growth followed the immediate re-implantation at other sites of 

 biopsy material removed in February 1955, at which time the histamine value 

 , was at its minimum. It is hoped to repeat this experiment in autotransplanta- 

 tion at a later date. 



Mice. The first transplantable mast-cell tumour to be discovered (p. 26) 

 was the so-called '3187 mast-cell sarcoma' which arose in a mouse undergoing 

 repeated skin painting with coal tar. Unfortunately this tumour had died out 

 some years before I became interested in the histamine content of tissue mast 

 cells. 



90 



