ON THE NATURE OF THE ABDERHALDEN 



REACTIONi 



J. BRONFENBRENNER 



According to Ehrlich's theory the parenteral introduction of 

 foreign protein causes the cells of the body to produce an excess of 

 specific receptors, which, at a certain period of the process, circu- 

 late freely in the blood, and are known to the Student of immunity 

 under the name of amboceptors, antibodies, or substances sensibili- 

 satrices. These specific antibodies are complex in character; and, 

 although they are directly responsible for the specificity of the pro- 

 tective processes in the body, they are not of themselves active prin- 

 ciples. It is to complement that Ehrlich and his school attribute the 

 power of action on antigen. 



The properties of the antibodies resemble those of enzymes in 

 very few respects, while they differ from them at many points. 

 According to Abderhalden, however, the parenteral introduction of 

 foreign protein results in the production of specific enzymes capable 

 of directly digesting antigen in vitro. I disagree with those who 

 think that Abderhalden has proved that these substances are enzymic 

 in character. On the one hand it is difficult to believe that the organ- 

 ism is able to supply so many specific enzymes; on the other, it is 

 improbable that the enzymes circulating in the blood are strong 

 enough to digest coagulated protein, as is the case in the Abder- 

 halden test. 



In our own experiments we tried to produce a specific enzyme by 

 repeated inoculation of rabbits with egg-white; and, although the 

 serum of these animals contained a very large amount of antibodies, 

 a Mett-tube filled with coagulated egg-white failed to show even 

 the slightest traces of digestion of the egg-white after suitable Im- 

 mersion in such serum. This and the results of other experiments 

 led US to conclude that either the enzymes on which the supposed di- 



iDiscussion at a meeting of the Pennsylvania State Medical Society, at 

 Pittsburgh, September 22, 1914- See also Proceedings of the Columbia Univer- 

 sity Biochemical Association, Dec. 4, IQM; Biochem. Bull., 1915, iv, p. 211. 



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