PROTEIN SENSITIZATION OR ANAPHYLAXIS 341 



This is a plausible and attractive statement, and we are 

 inclined to believe that there is truth in it, but we fail to 

 see any reason for designating it as a "physical theory." 

 It starts out with the assumption that proteins contain a 

 poison and the theory is an explanation of the modus operandi 

 of the chemical poison. The endothelial cells are sensitized 

 and pour out a ferment, antithrombin, in increased quantity. 

 That the endothelial cells are involved in sensitization we 

 held as long ago as 1907. That the permeability of the walls 

 of the capillaries is increased under the action of protein 

 poison has been frequently demonstrated by the general 

 diapedesis. We found this true even when rabbits died as 

 the result of a single large dose of egg-white. 



There is, however, one very important point in which 

 the theory of Nolf differs from ours. In his theory the cause 

 of death on reinjection is not due to the cleavage of the 

 protein introduced, but is due to the action of the antithrom- 

 bin on the blood. He holds that the fact that intravenous 

 reinjections are so much more effective both in dose and in 

 time than intraperitoneal and subcutaneous administrations 

 is in favor of his theory, and we are inclined to agree with 

 him on this point. However, anaphylactic shock cannot be 

 due wholly to rendering the blood non-coagulable, because 

 this may be done by injections of hirudin without shock. 

 Doerr objects to our theory on the ground that anaphylactic 

 shock follows reinjection so quickly that there is not time 

 for a ferment to split up the injected protein and liberate 

 a poison; but Nolf's theory also depends upon ferment 

 action. The sensitized endothelial cells must be awakened 

 by the reinjection, must pour out their abnormally accumu- 

 lated ferment, and this must act, not on the injected protein, 

 as we suppose, but on the blood. According to either theory, 

 certain cells are sensitized and store up zymogen, which is 

 activated on reinjection. This ferment acts either upon the 

 injected protein or on the proteins of the blood. It seems 

 to us that the time objection made by Doer to our theory 

 is quite as applicable to that of Nolf. The latter is, after 

 all, only a modification of the former. 



