ANAPHYLAXIS OR HYPERSUSCEPTIBILITY 303 



be taken as an axiom for all cases in which the antigen is an unformed 

 protein in solution. Whether or not it holds universally good in the 

 case of cell anaphylaxis is a question too complicated to be discussed 

 here. When the antigen and antibody are injected simultaneously or 

 within a very short period of one another, no anaphylactic symptoms 

 occur. The study of this interval has gradually led to the belief that 

 the anaphylactic reaction, whatever it may be, takes place upon the 

 body cells and that the interval is necessitated by the time required for 

 the anchoring of the antibodies to the cells of the body. Experiments 

 by Pearce and Eisenbrey 1 (1910) showed definitely that a sensitized 

 dog remained sensitized even when his entire blood volume is substi- 

 tuted with that of a normal dog. It has been made especially clear 

 by the introduction of direct methods of observation of the smooth 

 muscle cells of animals by Schultz 2 and Dale, 3 a method which has 

 been particularly developed by Weil. 4 It seems fairly clear from this 

 work and a volume of other researches which cannot be reviewed here, 

 that acute protein anaphylaxis as we see it in guinea-pigs and other 

 laboratory animals is due to the direct reaction between antigen and 

 a specific antibody when this reaction takes place upon the body cells 

 and not in the blood stream. Just how much influence the reaction 

 within the blood steam can exert or whether it takes any important part 

 in the phenomena is at present a matter of considerable doubt. 



An important observation made by Friedberger and Hartoch 6 and 

 much studied by others recently, also, has been the diminution of com- 

 plement or alexin in the serum of animals suffering from anaphylactic 

 shock. It has been shown that in passive anaphylaxis, at least simul- 

 taneously with the occurrence of symptoms, there is a marked diminu- 

 tion of alexin. Intravenous injections of substances which prevented 

 complement absorption in vitro (concentrated salt solution, for in- 

 stance) diminished shock and sometimes prevented it in sensitized 

 animals. They attributed this to the fact that complement was thereby 

 inhibited, and concluded that complement took an important part in 

 the reaction. Incidentally it may be mentioned that in experiments 

 upon the uterine contractions of sensitized guinea pigs, the writer with 



1 Pearce and Eisenbrey, Congr. Am. Phys. and Surg., 1910, viii. 



2 Schultz, Jour. Pharmacol. and Exper. Therap., 1910, i. 



3 Dale, Jour. Pharmacol. and Exper. Therap., 1913, iv. 



4 Weil, Jour. Med. Research, 27, 1913; 30, 1914; Proc. Soc. Exper. Biol. and Med., 

 1914, xi, 86. 



6 Friedberger and Hartoch, Ztschr. f. Immunitatsforsch., 1909, iii. 



