ANAPHYLATOXIN (PROTEIN POISON) 587 



Vaughan many years previously. After sensitization, a specific proteo- 

 lytic ferment is produced for the particular protein injected, the presence 

 of the specific in addition to the normal ferments constituting the differ- 

 ence between normal and sensitized animals. 



Since these studies show that, when incubated with normal serum, 

 bacteria and certain other proteins yield a soluble and active poison, 

 the question naturally arises why this reaction does not occur when 

 these proteins are first injected directly into the blood? Vaughan has 

 answered this question by assuming that the ferment is in a more avail- 

 able form in the serum than it is in the blood, since the ferment is prob- 

 ably largely a leukoprotease mainly derived from the disintegration of 

 leukocytes. Or it may be that the cleavage is carried on in the circulat- 

 ing blood beyond the point of the products constituting the protein 

 poison, or that the inclusion of the foreign protein by the phagocytes may 

 delay the disruption of the former. 



The Protein Matrix. While there is this consensus of opinion 

 among the adherents of the chemical or anaphylatoxin theory of ana- 

 phylaxis regarding the role of protein poison in the production of ana- 

 phylaxis, there is some diversity of opinion regarding the source of the 

 protein matrix, i. e., whether the protein that is broken down is the 

 protein injected or the protein of the person's own serum, especially 

 in view of the fact that mixtures of kaolin and normal guinea-pig serum 

 produce the poison in vitro. It has been suggested (a) That the 

 kaolin, agar, bacteria, etc., absorb the complement from the serum, 

 and that this renders the serum poisonous; (6) that the poison is 

 preformed in the serum, but that its action is neutralized by some 

 other constituent of the serum that is absorbed; (c) that the absorption 

 of some constituent of the serum leads to a, breaking-up of serum pro- 

 teins, with liberation of the poison. The latter view, as shown by Job- 

 ling and Petersen, 1 appears to be the most plausible. These writers 

 believe that the normal tryptic or proteolytic ferment of the blood is 

 held in check by an antiferment of the nature of unsaturated fatty acids, 

 and that laokin, bacteria, agar, etc., remove this antitryptic influence 

 by absorbing the lipoidal antiferment, setting the ferment free, which 

 then acts upon the serum protein, producing the toxic protein poison 

 (sero toxin). While Vaughan, Friedberger, and their collaborators 

 believe that the protein poison is derived from the injected protein, 

 Jobling and Petersen believe that the matrix is, indeed, the protein of 

 the animal's own serum. Doerr 2 likewise regards it as highly improbable 



1 Jour. Exper. Med., 1914, xix, 459 and 480. 



2 Handb. d. path. Mikroorgan., Kolle and Wassermapn, second edition-, ii, 947. 



