4A'.l/'//17..1A7.s' on ALLKIiOY 197 



teius in the blood stream, and that upon injection of a second dose 

 of the same protein these enzymes at once disintegrate it, and 

 some of the cleavage products being toxic the anaphylactic in- 

 toxication results. ]\Iany of the later developments in this field, 

 especially Abderhalden's studies on "protective ferments," have 

 added support to this hypothesis, so that in its fundamental concep- 

 tions it is now the most generally accepted explanation of the processes 

 involved in anaphylaxis.^^ 



Friedberger caiTied the matter a step farther by showing that if 

 serum from a sensitized animal is incubated for a short time with the 

 same protein, and in the presence of enough complement, a poison 

 is developed which produces the typical symptoms of anaphylactic 

 intoxication when injected into guinea-pigs. Tliis poison resists heat- 

 ing at 56°, but not at 65°, and is not a true toxin, for it will not 

 produce an antitoxin immunity. In the absence of complement, or 

 when the complement fixation is prevented by strong salt solution,^* 

 the poison (anaphylatoxin) does not develop, so that the anaphylactic 

 reaction falls into the same class as the lytic reactions, in which the 

 non-speeiMc serum complement is united to a cell by the specific am- 

 boceptor, and then causes lysis of the cell ; in anaphylaxis not an 

 organized cell but a complex protein molecule is disintegrated by the 

 complement, but in either case a poisonous substance may be liberated. 



This agrees with Vaughan's hypothesis in ascribing the poisoning 

 to products of protein disintegration formed by enzyme action, but 

 differs in that specific intermediary substances or amboceptors are sup- 

 posed to be developed by sensitization, rather than specific enz;ymes. 

 Friedberger is of the opinion that many or all the different immunity 

 reactions depend upon a single antibody, the different reactions merely 

 being different methods of demonstrating the presence of the anti- 

 body in tiie serum. The precipitin reaction differs from the anaphy- 

 lactic reaction, he contends, only in that in the latter the specific pre- 

 cipitate is (L'ssolved by complement, yielding the anaphylatoxin. 

 There are many objections ^^ to accepting this idea in its entirety, 

 which we shall discuss later, but the formation of a poison resembling 

 that of anaphylaxis, by a digestive action of complement fixed to the 

 antigen bj' the antibody, seems to be well established, both as regards 

 in vitro and in riro reactions. 



It would seem probable that proteins may yield a similar poison in 

 whatever way their hydrolysis is brought about, provided the cleav- 

 age is not too deep-seated. For example, Rosenow ^® has found that 



13 See Vaiighan, Amer. Jour. Med. Sci., 1913 (145), 161; Zeit. Immunitiit., 1011 

 (9), 458. Also a full review in his "Protein Split Products," Philadelpiiia, 191.3. 



14 Fricdherger's explanation of the inhibiting efieot of salt as interference witli 

 complement action, has been questioned. (See Zinsser, Arch. Int. Med 1915 

 (16), 238.) 



13 See Besredka et a/., Zeit. Immunitiit., 1912 (16), 249. 

 16 Jour. Infec. Dis., 1912 (11), 94 and 235. 



