438 IMMUNO-CATALYSIS 



at pH 7.3 to 7.5 ran parallel to its ability of splitting benzoyl-l-arginine 

 amide. It may also be pointed out that ficin, which is toxic to animals 

 (Molitor, et ah, 1941) and produces certain pathological symptoms 

 comparable to those produced in severe shock, is capable of splitting 

 specifically the amide grouping in benzoyl-l-arginine amide (Bergmann 

 and Fruton, 1941). Rocha e Silva expresses the view that most of the 

 histamine present in living cells is bound to arginine or to lysine and 

 can be liberated by the action of a ferment displaying the specificity of 

 trypsin. Rocha e Silva (1944) submitted his point of view in a schema- 

 tized manner, showing the possible nature of factors involved in the 

 liberation of histamine followed by the shock of animals. The scheme 

 perhaps presents the relationship of the various factors when proteo- 

 lytic enzymes, poisons and intracellular cathepsins are responsible for 

 shock. 



There are two types of experimental data which contradict the 

 postulate that the liberation of histamine related to a proteolytic action. 

 Mclntire and Roth (1950) reported that histamine is released very 

 rapidly from rabbit blood cells by two series of pure compounds 

 (primary aliphatic amines and alkyl-^S-carbomethoxypyridinium salts). 

 At 37°C. n-octadecylamine, 8 X 10~^M, will release all or nearly all of 

 the histamine from the normal rabbit blood cells. A maximum hista- 

 mine release results also when n-hexadecyl-/?-carbomethoxypyridinium 

 bromide is used at a concentration of 8 X 10~^M. At 37°C. the hista- 

 mine release by these compounds is 90% complete in one minute. 



In another study, Mclntire, Roth and Sproull (1950) investigated 

 the question of whether or not histamine release from sensitized rabbit 

 blood cells is dependent on the action of the liberated fibrinolysin as 

 postulated by Ungar and Mist (1949). They added crystalline soybean 

 trypsin inhibitor, which is a potent inhibitor of fibrinolysin, and 

 purified bovine fibrinolysin and artifibrinolysin to the systems they 

 studied. They reported that excessive concentrations of soybean trypsin 

 inhibitor and bovine antifibrinolysin failed to inhibit the histamine 

 release by antigen and the poor and inconsistent histamine release 

 by bovine fibrinolysin indicated that in vitro anaphylactic release of 

 histamine from rabbit blood cells does not depend upon fibrinolysin 

 activity. 



Our view concerning these problems differs from what has been 

 discussed above. Any interpretation of the phenomenon of shock 



