HYPERSUSCEPTIBILITY 365 



been accomplished but since the absorption of unchanged antigen by 

 these routes is ordinarily slight, little hope can be expected in this 

 direction for practical purposes. 



There are certain forms of protection against anaphylactic shock 

 produced by the injection of foreign sera, and other proteins and 

 processes non-specific as far as the particular anaphylactic mechan- 

 ism is concerned, but there is too little positive knowledge about 

 these to permit us to discuss them here. 



ANAPHYLATOXIN THEORIES, ETC. Vaughan and Wheeler 44 early 

 suggested that anaphylaxis might be a poisoning produced as fol- 

 lows. Antibodies are formed by the first injection, which on subse- 

 quent reaction with the antigen administered in the second injection, 

 lead to poisonous protein-split products. A similar idea was ad- 

 vanced by Wolf-Eisner. 45 Proceeding from this general concept, 

 Friedberger, whose extensive experimental work may be found in 

 many articles in the Zeitschrift f. Immunitatsforschung, elaborated 

 a theory of anaphylaxis which may be summarized in the following 

 way: When the antigen and antibody meet in the circulation, the 

 union of the two renders the antigen amenable to complement action, 

 and the action of the alexin or complement upon this complex splits 

 off from it a poison which he calls ' ' anaphylatoxin. ' ' He succeeded 

 in producing poisonous substances in vitro by treating specific pre- 

 cipitates as well as sensitized and unsensitized bacteria with alexin. 

 Injection of these substances into guinea pigs caused acute death, 

 analogous in symptoms to anaphylaxis. Friedberger and Hartoch 46 

 showed that there was a diminution of alexin in the serum of animals 

 suffering from acute shock in the course both of active and of 

 passively transmitted anaphylaxis. He showed that the intravenous 

 injection of substances which inhibited complement action in vitro, 

 such as, for instance concentrated salt solution, would diminish and 

 sometimes prevent shock in sensitized animals, a phenomenon, how- 

 ever, which the writer with Lieb and Dwyer 47 showed to be due 

 to diminution of the irritability of smooth muscle caused by hyper- 

 tonic salt. It was subsequently shown, however, that similar poisons 

 could be produced from boiled as well as from normal bacteria, that 

 they could be produced by the treatment of fresh guinea pig serum 



44 Vaughan and Wheeler, Jour. Infec. Dis., 4, 1917. 



45 Wolf-Eisner, Berl. klin. Woch., 1904. 



48 Friedberger and Hartoch, Zeit. f. Immunitat., 1909, 3. 



47 Zinsser, Lieb and Dwyer, Jour. Exper. Biol. and Med., 12, No. 8, 1915. 



