PROTEIN SENSITIZATION OR ANAPHYLAXIS 233 



Later, Rosenau has announced that guinea-pigs kept in 

 stables with horses become sensitized to horse serum. 



Wells and Osborne 1 have studied the anaphylactic reac- 

 tions of some pure vegetable proteins, such as the globulins 

 from castor bean, flax-seed, and squash-seed, edestin from 

 hemp-seed, excelsin from Brazil nuts, legumins from peas 

 and vetch, vignin from cow peas, glycinin from soy beans, 

 gliadin from wheat and rye flour, hordein from barley, and 

 zein from maize. " It has been found that all these proteins 

 cause typical anaphylactic reactions in sensitized animals, 

 with all features essentially the same as when serum and 

 other animal materials containing proteins are used. The 

 minimum doses which produce sensitization and the time 

 of incubation are about the same as with animal proteins 

 but as a rule the symptoms are of somewhat slower onset 

 and less stormy course than are those obtained with foreign 

 sera, and the minimum intoxicating doses are larger. There 

 are also considerable differences in the toxicity of the several 

 vegetable proteins to sensitized animals, but the reasons for 

 these differences have not yet been investigated. The most 

 toxic proteins as measured by the frequency of severe and 

 fatal reactions, were the globulin of squash-seed, vignin, 

 excelsin, and castor-bean globulin, which usually caused 

 death when given in 0.1 gram doses to properly sensitized 

 animals. Edestin caused the least severe reactions of any 

 of the proteins, while hordein and glycinin seldom caused 

 fatal reactions. Nevertheless the minimum sensitizing 

 and intoxicating doses of edestin and squash-seed globulin 

 are essentially the same. The influence of the food of the 

 guinea-pig upon the anaphylactic reaction is of particular 

 importance in experiments with vegetable proteins, since 

 the natural food of the guinea-pig is vegetable. Experiments 

 showed that continuous feeding with a vegetable protein 

 rendered guinea-pigs immune to this protein, so that they 

 could not be sensitized to it. Although brief feeding with 

 animal proteins (cows' milk, foreign sera, egg albumen) 



1 Jour. Infect. Dis., 1911, viii, 66. 



