592 ANAPHYLAXIS 



"sensibilisinogen" and "antisensibilisin." When injected the first 

 time the former develops in the body a substance called "sensibilisin," 

 and on reinjection the sensibilisin and antisensibilisin continue to form 

 a poison that acts on the nervous system. 



4. Gay and Southard believe that, as a result of the first injection 

 of serum, there remains in the circulation a protein substance called 

 "anaphylactin," which is slowly absorbed and continues to stimulate 

 the cells, leading to an abnormal affinity for the homologous protein, 

 which, on reinjection, leads to anaphylactic shock. 



5. Vaughan and Wheeler are of the opinion that, with the parenteral 

 introduction of a foreign protein, the body-cells are stimulated to produce 

 a specific zymogen or ferment that digests it. The protein of the first 

 injection is so slowly digested that the effects are not recognizable. After 

 the protein of the first injection has been disposed of, the new ferment 

 continues to be formed in the cells, and on the second injection, after the 

 proper interval has been allowed to elapse, this zymogen is activated and 

 splits up the protein, which promptly and abundantly results in the pro- 

 duction of the symptoms of anaphylactic shock. Vaughan believes 

 that there is a non-specific poisonous group or moiety in each protein 

 molecule which, when liberated by the ferment, is responsible for ana- 

 phylaxis. This poisonous group is held as being the same in all pro- 

 teins, and hence the similarity of lesions and symptoms of anaphylactic 

 intoxication in animals regardless of whether the protein is of animal, 

 vegetable, or bacterial origin. The nature of the ferment is not clear. 

 In 1907 they regarded it as a zymogen a theoretic labile chemical body 

 resulting from intramolecular rearrangement in the protein molecules 

 of the cell. Little is known of the action of these ferments except that 

 in some manner they cause cleavage of the protein molecule and libera- 

 tion of the toxic moiety. Later, Vaughan speaks of the ferment as 

 consisting of an amboceptor and a complement, the ferment (pre- 

 sumably the complement portion) being inactivated by a temperature of 

 56 C. and reactivated on the addition of serum and organic extracts. 

 Although Vaughan's theory best explains the nature and source of the 

 anaphylactic poison, that of Friedberger explains the production of the 

 "ferment," or rather the protein sensitizer (amboceptor), which, with 

 a complement, digests the protein and sets free or produces the protein 

 poison. 



6. Friedberger has attempted to explain anaphylaxis on the basis 

 of Ehrlich's side-chain theory of the action of antigens and the produc- 

 tion of antibodies similar to toxin-antitoxin immunity. This theory 



