156 ANAPHYLAXIS 



chial mucous membrane of guinea-pigs is especially thick and folded 

 in such a manner that relatively slight contractions of the muscle 

 fibers, which in other animals would lead to no untoward results, 

 might be sufficient in the guinea-pig to effect complete occlusion 

 of the bronchial lumen. Evidently, however, our knowledge of 

 existing conditions is as yet too meager to warrant any far-reaching 

 conclusions. 



Mechanism of Antianaphylaxis. As regards the mechanism which 

 underlies the production of antianaphylaxis. Friedberger has sug- 

 gested that it might be due to the absorption or neutralization 

 (sc., inactivation) by the second dose of antigen of any antibody 

 that may be present at the time, so that a subsequent injection of 

 antigen does not meet with enough antibody to form a fatal dose 

 of poison. Antianaphylaxis will hence be observed during the pre- 

 susceptible stage, because not enough antibody has as yet been 

 formed and during the susceptible stage (if a subfatal dose of anti- 

 gen is injected), because all or most of the antibody is used up by 

 the subfatal dose of the antigen. This principle is now practically 

 utilized when the necessity arises of reinjecting a patient who has 

 been sensitized by a previous injection of alien serum (antitoxin) . The 

 individual then receives a very small dose of the serum to be admin- 

 istered about an hour or two before the full dose is given, 

 or the serum may be administered so slowly that the antianaphyl- 

 actic state can actually develop during the injection (see Adminis- 

 tration of Diphtheria Antitoxin). 



Friedberger's explanation of the mechanism underlying the devel- 

 opment of antianaphylaxis, as outlined above, is in perfect accord 

 with the experimental facts, such as its abrupt development, its 

 specificity and even with the apparently contradictory observation 

 that anaphylactic susceptibility can be passively transferred to 

 another animal even during the antianaphylactic state (as a portion 

 of the anaphylactic antibody may have escaped neutralization). 

 As Pfeiffer and Mita, moreover, have shown, the proteolytic fer- 

 ment which may be demonstrated in the serum of the sensitized 

 animal, disappears with the development of antianaphylaxis. 



Strongly in support of Friedberger's view also is the fact that 

 sensitized animals which have been rendered antianaphylactic 

 with the homologous serum are thereby not protected against the 

 anaphylatoxin itself. 



