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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 (Araki), 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 (Kuhne 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. Mucin is dissolved and split by trypsin, while chitin and horn
substance do not seem to be acted upon by the enzyme. Oxyhemoglobin
is decomposed by trypsin with the splitting off of hsematin. 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
Kuhne 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.
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