THE PARENTERAL INTRODUCTION OF PROTEINS 369 



titer of the serum, or, in other words, lessen the digestive 

 action of the blood, and they propose to distinguish between 

 primary and secondary protein toxicoses by determining 

 the antitryptic titer of the blood serum. 1 They state that 

 the curve of the antitryptic serum titer in retention uremia 

 after double nephrectomy in rabbits is similar to that of 

 anaphylactic shock and hemolytic poisoning. Before the 

 development of symptoms of poisoning the antitryptic 

 titer rises above the normal (owing to the accumulation 

 of digestion products). 



It must be evident that the presence of a specific proteo- 

 lytic ferment is not necessary in all cases to split up proteins 

 with the liberation of the protein poison. As has been 

 stated, Friedberger and many others have found that the 

 protein poison is liberated from bacterial proteins by diges- 

 tion with the normal serum of guinea-pigs. In this there 

 can be no question of a specific ferment. The animals 

 supplying this serum have not been sensitized with bacterial 

 or any other proteins. They are normal, untreated animals; 

 besides, there is nothing specific in this reaction, since the 

 same poison is obtained from diverse bacterial proteins. 

 As we have held for years, every protein molecule contains 

 a poisonous group, and whenever and by whatever agent 

 the protein molecule is disrupted, the poisonous group 

 may be set free. The disrupting agent may be a chemical 

 substance, a specific or a non-specific ferment. Failure 

 to grasp this point has, in our opinion, led more than one 

 investigator into error. At one time Friedberger stated 

 that our poison cannot be the true anaphylactic poison 

 because its formation is not specific. If this be true of our 

 poison it is also true of his so-called anaphylatoxin. When 

 a protein is digested or split up there is one stage in the 

 process when the poisonous group is liberated. This may 

 not always be evident because when the cleavage is carried 

 one step farther the poison itself is destroyed. This is true 



1 The details of this procedure are given in their paper, Zeitsch. f. 

 Immunitatsforschung, 1912, xvi, 38. 

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