PROTEIN SENSITIZATION OR ANAPHYLAXIS 241 



Doerr and Russ were unable to sensitize mice, but Braun 

 succeeded after repeated injections and Ritz after a single 

 treatment, when the reinjection was made intravenously. 



Goats and sheep have been sensitized by Friedemann 

 and Isaac, 1 and horses and birds by Doerr. 



Dogs are not easily anaphylactized. Friedemann and 

 Isaac, also Remlinger, 2 failed, and the former suggested 

 that it was due to the fact that this animal is largely car- 

 nivorous, but Biedl and Kraus, 3 using the finer method 

 of measuring anaphylactic shock by fall in blood pressure, 

 has made this animal of great value in studying the phe- 

 nomena of anaphylaxis. The dog has also been employed 

 by Arthus, 4 by Manwaring, Pearce, Edmunds, and others. 



Vaughan and Wheeler failed to sensitize cats by a single 

 intra-abdominal injection of egg-white, but repeated injec- 

 tions were not tried. More recently it has been shown 

 that the cat can be easily sensitized. Up to the present 

 time no animal thoroughly tested has failed to respond 

 to protein sensitization. 



We are without sufficient data to determine with any 

 certainty the relative susceptibility of man to protein 

 sensitization. As with other animals, man's susceptibility 

 evidently varies within wide limits with the protein supplying 

 the anaphylactogen. Pirquet and Shick have shown that 

 a high degree of sensitization may result from a single 

 relatively small dose of a heterologous serum. The high 

 degree of sensitization shown by many in hay fever and 

 in susceptibility to certain foods raises questions which 

 will be discussed later. 



Period of Incubation. By the period of incubation we 

 indicate the interval of time between the introduction of 

 the anaphylactogen and that time when the body is recog- 

 nizably disturbed by a reinjection of the same or a closely 

 related protein. It is quite properly designated as the 



1 Zeitsch. f. Exp. Path. u. Ther., i, 513. 



2 Compt. rend, de la Soc. biol., Ixii, 23. 



3 Wien. klin. Woch., 1909, 363. 



4 Compt. rend, de 1'Acad. Sci., cxlviii, 1002. 

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