ANAPHYLACTOGENS, OR ALLERGENS 579 



ANAPHYLACTOGENS, OR ALLERGENS 



So far as is now known, only proteins may become anaphylactogens, 

 and with the exception of gelatin and a few other proteins, practically 

 any soluble protein will produce sensitization and intoxication of sus- 

 ceptible animals. Bacterial substances, extracts of plant tissues, 

 purified vegetable proteins, and proteins derived from invertebrates and 

 cold-blooded vertebrates have all been found capable of acting as 

 anaphylactogens when introduced in a soluble and unaltered condition 

 into an animal. 



The proteins concerned must be foreign to the circulating blood of 

 the injected animal, but they may be tissue proteins of the same animal 

 e. g., syncytial cells that are not normally present in the blood. Indeed, 

 Uhlenhuth and Haendel 1 claimed to have sensitized a guinea-pig with 

 the dissolved lens of one eye so that it reacted to a subsequent injection 

 of the lens of the other eye. Proteins in solution are more active than 

 those in suspension or in partial solution, and in general tissue proteins 

 are less active than proteins in the blood, lymph, and secretions, but 

 even keratins may produce anaphylaxis when dissolved (Krusins 2 ), 

 Uhlenhuth 3 has obtained positive results with proteins from mummies. 

 As previously stated, the altered protein of an animal may be reinjected 

 again into the animal and induce an anaphylactic reaction. Recently 

 Richet 4 has directed attention to this phenomenon, which he calls 

 "indirect anaphylaxis," through observing an intense leukocytosis in a 

 dog which reached the maximum on the eighth day following a second 

 chloroformization. 



Non-protein Anaphylactogens. As with other immunologic reac- 

 tions, observations have been made that are interpreted as indicating 

 that non-protein substances are capable of producing anaphylaxis; 

 thus Pick and Yamanouchi 5 sought to demonstrate the antigenic 

 properties of alcohol-soluble constituents of horse and beef serum, but 

 conservatively concluded that their results may have been due to a com- 

 bined action of protein and fat combinations. Similar conclusions were 

 also drawn by Uhlenhuth and Haendel 6 in their study of animal and 



1 Zeitschr. f. Immunitatsf., 1910, 4, 761. 



2 Arch. f. Augenheilk., SuppL, 1910, 47, 47. 



3 Zeitschr. f. Immunitatsf., 1910, 4, 774. 



4 Quoted in Jour. Amer. Med. Assoc., 1914, Ixii, 711. 



5 Zeitschr. f. Immunitatsf., 1909, 5, 676. 



6 Zeitschr. f. Immunitatsf., 1910, iv, 761. 



