INFLUENCE OF THE FOOD ON THE TISSUES 57 



It will be noted that, under the above conditions, the food has had 

 no influence on the composition of the proteins of the serum. The 

 authors held that the necessary change took place in the intestinal wall, 

 the extra glutamic acid having been split off and probably absorbed 

 separately. Abderhalden, Funk and London (41) again investigated 

 this question. In this series of experiments they used dogs with Eck's 

 fistula and fed the animals with food of known composition (of known 

 glutamic acid content). The blood was examined before and after the 

 special feeding. The foods used were flesh, egg albumin and gliadin. 

 As the result of their experiments they concluded that no food protein 

 was to be found in the blood and that by the chemical method as be- 

 fore they were unable to discover any influence of the constitution of 

 the food on the constitution of the serum protein, more especially as 

 regards the content in glutamic acid. They also examined the nature 

 of the protein in the blood cells but found that it too was unchanged. 

 Then Abderhalden, Gigon and Strauss (40) showed that although the 

 animals were fed on widely differing foods, the tissues of cats, rabbits 

 and hens were practically identical in constitution, i.e. with about 3-3 

 per cent, of glycine and over 1 3 per cent, of glutamic acid. Orgel- 

 meister (310) again has shown that the arginine content of tissues could 

 not be altered by feeding the animal on foods rich in arginine. Nor 

 was he able to alter the arginine content of the tissues by the ad- 

 ministration of substances like benzoic acid which might have been ex- 

 pected to combine with the arginine. 



Gitkins (153) studied the composition of the blood during hunger, 

 and found, like Burckhardt (79), Lewinski (256) and others, a distinct 

 increase of the globulin fraction of the serum during hunger. He also 

 noted that if bread were used in the subsequent feeding of the animal 

 the blood more rapidly returned to its normal composition than when 

 a meat diet was given. He suggested that the albumin of the serum 

 came from the food, and the globulin from the tissues. It must not 

 be forgotten, however, that Moll (287) has stated that he could convert 

 in vitro albumin into globulin with the greatest of ease by heating the 

 serum to 58 for a short period. 



