PROTEIN SENSITIZATION OR ANAPHYLAXIS 289 



way and far from pure, kills guinea-pigs when injected 

 intracardiacly in doses of 0.5 mg. The minimum fatal dose 

 of the pure poison as split off by the ferment in the body 

 must be much less than this. It will be seen from this 

 that the proteins of the reinjection, even when the smallest 

 fatal dose is used, probably contain enough of the poison 

 to kill. In the second place the ferment developed in 

 anaphylaxis is specific. It splits up its own anaphylactogen 

 and no other protein. There is no reason for supposing 

 that it can digest the body proteins. It seems to us that 

 this supposition is wholly untenable. It is contrary to all 

 we know about the specificity of the anaphylactic ferment. 

 How then may we account for the greatly increased nitrogen 

 metabolism? When the foreign protein is split up the 

 split products chemically react with the protein molecules 

 of the animal's body. The liberated poison tears off the 

 basic groups from the body molecules, and this goes on 

 to the extent and during the time that the cleavage con- 

 tinues. We see this in its most marked form in the Arthus 

 phenomenon, for in this the process is more localized. We 

 have shown that foreign proteins injected intravenously 

 in rabbits soon disappear from the circulating blood, and 

 after this they may be detected in the skin and in other 

 tissues. We have already seen (p. 262) to what extent 

 destruction of tissue may occur in the Arthus phenomenon. 

 There is an additional explanation of the augmented 

 nitrogen metabolism. The protein matter resulting from 

 the disruption of the molecules of the body by the split 

 products from the anaphylactogen is digested by the normal 

 non-specific parenteral ferments, and in this way nitrogen 

 elimination is increased. As has been stated, Friedberger 

 has obtained the poison by digesting precipitates and 

 bacterial cells with homologous anaphylactic sera. As 

 thus obtained and injected intravenously it induces ana- 

 phylactic shock and death. He has obtained like results 

 by digesting bacterial cells with the normal serum of guinea- 

 pigs. It might be assumed from this that Friedberger's 

 poison is not the true anaphylactic poison, but in our 

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