350 PROTEIN POISONS 



In the light of later research, some criticism of the above 

 given conclusions reached by Friedemann and Isaac may 

 be made. Foreign proteins when introduced parenterally 

 are poisonous. In some, the poisonous action is due to 

 ferments, but all are poisonous, even when the ferment 

 action has been destroyed by heat. It is only a 'question 

 of dosage. Even egg-white or horse serum injected intra- 

 venously in sufficient doses will kill dogs and rabbits. 

 Saturat on of the body cells with any foreign protein inter- 

 rupts their function. The protein foods of the body cells 

 are carefully prepared physiologically. The foreign pro- 

 teins eaten by the animal are broken into non-protein 

 bodies, and these pieces are put together again after a 

 model which is peculiar to that species of animal to which 

 the feeder belongs. In this way the specific albumins and 

 globulins of the blood of each species are constructed, 

 and these supply the normal protein foods for the body 

 cells. Foreign proteins parenterally introduced are digested, 

 if the amount be not too large. This digestion is carried 

 out in part in the intestines, and other body cells acquire 

 the function of digesting a limited amount of the protein 

 introduced. Certainly the digestive products formed in 

 the intestine are fit for assimilation, and it may be that 

 those formed in other parts are also utilizable, but the 

 capability of the body of taking care of proteins parenterally 

 introduced is limited, and in large doses all foreign proteins 

 thus administered are poisonous. Whether this is also 

 true of homologous sera we do not have sufficient data to 

 determine. 



Bankowski and Szymanowski 1 find that normal human 

 blood, when injected intravenously into guinea-pigs, kills 

 with the symptoms of anaphylactic shock in doses of 0.5 

 per cent, of the body weight of the animal. In typhoid 

 fever the minimum fatal dose falls to 0.25 and in scarlet 

 fever and measles to 0.13 per cent, of the body weight of 

 the animal. Fetal human blood is well-nigh atoxic; when 



1 Zeitsch. f. Immunitatsforschung, 1913, xvi, 330 



