HISTAMINE-LIBERATION IN MOUSE AND RAT 



in the tissues has been liberated. Further injections are toxic for reasons which 

 are not yet clear. 



It is evident, therefore, that no simple hypothesis is adequate to explain 

 the action of compound 48 80 as a liberator of histamine. Compelling evidence 

 has been presented earlier that the chief repository of the tissue histamine is 

 the mast cell: this would appear to be true for all species. On the other hand, 

 compound 48 80, which is so effective in the rat, is only a moderately successful 

 liberator of histamine in the mouse, and can hardly be described as a histamine- 

 liberator for the guinea pig in which other toxic symptoms predominate 

 (Feinberg and Sternberger, 1955). 



The solution of one problem only brings others to light. It would seem 

 that the next step is to enquire more closely into the structure and composition 

 of the mast granule in various species and the means whereby histamine is 

 bound in the cell. This may suggest a basis for the mechanism of its release. 



115 



