112 CHEMISTRY OF THE PROTEIDS CHAP. 



Steyrer l found cadaverin during pancreatic digestion, Lawrow 2 and 

 Langstein 3 during gastric digestion ; Lawrow found putrescin ; 

 oxyphenylethylamin was found by Langstein during gastric digestion, 

 and by Emerson 1 during pancreatic digestion. These reactions 

 depend, of course, on special enzymes, and not on pepsin or trypsin. 

 Jacoby 4 has observed that the nitrogen which can be split off' by 

 means of magnesia, is increased during the autodigestion of the liver, 

 and that the fixed nitrogen becomes loosened somehow. 



The question of des-amination of amino-acids has been specially 

 gone into by Lang, 5 who studied the action of finely-divided tissues 

 (liver, kidney, lymph-glands, supra-renals, testes, pancreas, intestinal 

 mucous membrane, spleen, muscle) on mono -amino-acids (glycocoll, 

 tyrosin, phenylalanin, leucin, cystin), on acid-amides (asparagin, 

 glutamin, acetamide), and also on urea and glucosamin. 



All the tissues just mentioned act vigorously on asparagin and 

 glutamin ; glucosamin is readily broken up by the kidney and supra- 

 renals, to a certain extent by the intestine, testis, liver, and spleen, 

 very slightly by muscle, and not at all by the pancreas ; urea was 

 acted upon by the pancreas and to a certain extent by the liver, which 

 also acts on glycocoll, acetamide, leucin, and uric acid. Lymph-glands 

 and the spleen have no action on glycocoll. It will be seen that the 

 power of desamination varies not only greatly amongst different organs 

 but also as regards the individual amino-acid radicals which are 

 subjected to the influence of the tissue-compounds. 



When glycocoll is injected intravenously in dogs, a small percent- 

 age is excreted unchanged by the kidneys, while the greater part is 

 desaminated in the tissues, leading thereby to an increase of ammonia 

 in the blood, according to Salaskin and Kowatevsky. 6 



Amide-splitting enzymes are discussed by Shibata (see p. 99). 7 



Trypsin and erepsin do not split off 7 agimonia, 8 while arginase 

 splits off urea as shown above. Albumins are altered beyond the 

 stage of the amino-acids, according to Kutscher, 9 for this observer 

 failed to obtain arginin, tyrosin, glutaminic and aspartic acids from 

 autodigested thymus. 



1 R. L. Emerson, Hofmeister's Beitr. 1. 501 (1902). 



- D. Lawrow, Zeitschr. f. physiol. Chem. 33. 312 (1901). 



3 L. Langstein, Hofmeisters Beitrage, 2. 229 (1902). 



4 M. Jacoby, Zeitschr. f. physiol. Chem. 3O. 149 (1900), 33. 126 (1901). 



5 S. Lang, Hofmeisters Beitrage, 5. 321 (1904). 



6 Salaskin and Kowatevsky, Zeitschr. f. physiol. Chem. 52. 410(1904). 



7 K. Shibata, Hofmeister's Beitrage, 5. 384 (1904). 



8 J. Mochizuki, ibid. 1. 44 (1901) ; 0. Cohnheim, Zeitschr. f. physiol. Chem. 35. 

 134 (1902). 9 F. Kutscher, ibid. 34. 114 (1901). 



