508 DIGESTION. 



(KUTSCHER and LOHMANN 1 ) . If putrefaction is not completely pre- 

 vented, still other bodies occur which will be considered later in con- 

 nection with the putrefactive processes in the intestine. 



The Action of Trypsin upon other Bodies. The nucleoproteins and 

 nucleins are so digested that the protein complex is separated from the 

 nucleic acid and then digested. The nucleic acids may, nevertheless, 

 be somewhat changed (AEAKI), which is probably brought about by 

 another enzyme, the nuclease (SACHS). A cleavage of nucleic acids with 

 the setting free of phosphoric acid and purine bases is, according to 

 IwANOFF, 2 not brought about by trypsin. The splitting is first pro- 

 duced by the action of nuclease or erepsin (see page 493). Gelatin is 

 dissolved and digested by pancreatic juice. A cleavage with the sepa- 

 ration of glycocoll and leucine does not occur (KtiHNE and EWALD), or 

 only to a trivial extent (REICH-HERZBERGE 3 ) . 



The gelatin-forming substance of the connective tissues is not directly 

 dissolved by trypsin, but only after it has been treated with acids or 

 soaked in water at 70 C. By the action of trypsin on hyaline cartilage 

 the cells dissolve, leaving the nucleus. The matrix is softened and 

 shows an indistinctly constructed network of collagenous substances 

 (KUHNE and EWALD). The elastic substance, the structureless membranes, 

 and the membrane of the fat-cells, are also dissolved. Parenchymatous 

 organs, such as the liver and the muscles, are dissolved all but the nuclei, 

 connective tissue, fat-corpuscles, and the remainder of the nervous 

 tissue. If the muscles are boiled, then the connective tissue is also 

 dissolved. Mudn is dissolved and split by trypsin, while chitin and horn 

 substance do not seem to be acted upon by the enzyme. Oxyhwmoglobin 

 is decomposed by trypsin with the splitting off of haematin. Trypsin 

 splits off large amounts of hydriodic acid from diiodotyrosine (OSWALD 4 ). 

 Trypsin has no action upon fats and carbohydrates. 



The action of trypsin on simply constructed substances of known 

 constitution such as acid-amides, polypeptides, is of especially great 

 interest. In this regard we have the somewhat earlier investigations 

 of GULEWITSCH, GONNERMANN, and ScHWARZSCHiLD, 5 but the investi- 



1 Fischer and Abderhalden, Zeitschr. f. physiol. Chem., 39; Emerson, Hofmeister's 

 Beitrage, 1; Levene, Zeitschr. f. physiol. Chem., 37; Kutscher and Lohmann, ibid. 

 39; Kutscher and Otori, ibid., 43, and Centralbl. f. Physiol., 18. 



2 Iwanoff, Zeitschr. f. physiol. Chem., 39, which also contains the literature; Sachs, 

 ibid., 46. 



3 Kiihne and Ewald, Verh. d. naturh.-med. Vereins zu Heidelberg (N. F.), 1; Reich- 

 Herzberge, Zeitschr. f. physiol. Chem., 34. 



4 Zeitschr. f. physiol. Chem. 62, 432 (1909). 



5 Hofmeister's Beitrage, 4, where the other works are also cited. 



