202 CHEMISTRY OF THE IMMUXITY REACTIOXS 



but there is no lack of theories. The original explanation was that 

 anaphylatoxin formation by specific antisera is the result of digestion 

 of antigen in vitro by the action of complement united to the antigen 

 by the immune antibody. For the formation of anaphylatoxin by 

 inert finely divided particles, the explanation advanced was that the 

 highly developed surfaces of these particles either activated comple- 

 ment, or united it to the serum proteins so that it digested them. 

 Jobling^^^ has advanced the hypothesis that normal serum antifer- 

 inents, which are believed by him to be lii)oidal in nature, are bound 

 by the particles or by specific precipitates, so that the complement is 

 free to attack the serum proteins. In any case, it is now generally 

 agreed that the poisonous substance is derived chiefly, if not entirely, 

 from the serum and not from the antigen, even in the case of ana- 

 phylatoxin formation by specific antigen-antibody-complement reac- 

 tions.^^"^ Furthermore it seems to be the same, as far as we can analyze 

 it by pharmacological methods, no matter what protein it is derived 

 from, or whether manufactured by immune or by nonspecific reactions, 

 or by chemical means, such as that of Vaughan. 



Jobling, who holds to the importance of anaphylatoxin formation 

 as the cause of anaphylactic intoxication, presents the following con- 

 ception of anaphylaxis : During the course of sensitization there oc- 

 curs the mobilization of a nonspecific protease, which is greatly in- 

 creased during acute anaphylactic shock; at this time there is also a 

 decrease in antiferment which permits proteolysis of the animal's own 

 proteins. As a result, there is to be found an increase in noncoagula- 

 ble nitrogen and amino-acids of the blood, and a decrease in serum 

 proteases. "The acute intoxication is brought about by the cleavage 

 of serum proteins through the peptone stage by a non-specific protease. 

 The specific elements lie in the rapid mobilization of this ferment and 

 the colloidal serum changes which bring about the change in anti- 

 ferment titer." 



The Anaphylactic Antibody (Anaphylactin). — That anaphylaxis, like 

 other immunity reactions, depends upon the presence of sjiecific anti- 

 bodies in the blood of the sensitized animal, is sho^\^l by the produc- 

 tion of passive anaphylaxis in normal animals, by injecting into them 

 a few cubic centimeters of blood or serum from a sensitized animal. 

 Such animals become sensitive in a few hours to the specific antigen, 

 no matter what species of animal furnishes the serum, showing that 

 various anaphylactins can unite with the same complement, altliough 

 strongly specific as to the antigen. In active sensitization the ana- 

 phylactin appears in the blood in ap])re('iable (luantities about eight 



siKZeit. Tnimunilii).. 1014 (2:n, 71: Jour. Kxp. Med.. 101.1 (22). 401. 



3iii 1'liat tlip antigen nuist be dijiostihlo, liowin-or, ia siijri;osto(l l)y the observa- 

 tion of Ten. Broeok (Jour. Biol. Chem., 1014 (17), IM'tO) that proteins raeemi/ed 

 by Dakin's method, wliicli cannot be dijjested by proteolylie en/yines. a)'e unable 

 to cause anapliylaxis. 



