Chapter VIII 



THE EFFECTS OF HISTAMINE-LIBERATORS ON THE 

 MAST CELLS OF THE RAT 



(See Riley, 1953/?) 



IN the introductory statement of the reasons for choosing the functions of 

 the tissue mast cells as a subject for research, it was argued that circum- 

 stantial evidence is already available which points to the mast cell being 

 at least one of the sources of tissue histamine. The main reservoir of both 

 heparin and histamine in the dog is thought to be the liver, the 'shock organ' 

 of this species (Rocha e Silva, 1952), and the heparin moiety is generally 

 attributed to the mast cells which are abundant in the liver of the dog (Wilander, 

 1938). The apparent absence of heparin in states of shock in other animal 

 species at first sight suggests that in the dog the association of heparin and 

 histamine is fortuitous, but the application of histamine-liberators to the rat 

 now to be described indicates that in this species too there may well be a closer 

 relationship than has as yet been realized and that histamine as well as heparin 

 may come from a common source, the tissue mast cells. 



Materials and methods 



Experimental animals. Adult male and female rats of the Wistar strain, 

 wt. 175-225 g., were used. 



Solutions for injection. The histamine-liberators and the concentrations 

 in which they were given by intravenous injection are shown in the accom- 

 panying table. 



Table I 



Chemical histamine-liberators : sources and dosage 



59 



