PROTEIN METABOLISM 85 
able to prove an increase. Kutscher and Seemann (/.c.) were 
unable, in their experiments, to find the crystalline products 
which they isolated from the contents of the intestine during 
digestion, either in the intestinal wall or in the blood. They 
discovered, however, in the wall of the intestine biuret-free 
extractive bodies which, on treatment with boiling acids, yielded 
leucin. They drew the conclusion from this observation that 
the leucin (and probably other crystalline products) absorbed 
from the canal is linked up with some other substance or 
substances into bodies of a more complex nature in the intestinal 
wall. Embden and Knoop (/.c.) were quite unable to prove 
that any synthetic action ever took place in the walls of the 
small intestine, when working, at any rate, with surviving gut 
outside the body. This is quite the reverse of what Glaessner’ 
claimed to have found in the case of the gastric mucous mem- 
brane. This worker stated that, as Hofmeister” had previously 
found, if the albumoses present at the time of digestion be 
allowed to remain in contact with the isolated mucous mem- 
brane of the stomach, they for the most part disappear as 
such, and that in their place appears a coagulable protein 
body. Concerning the nature of this protein Glaessner says 
nothing, but holds its formation to prove that by the altera- 
tion of the albumose a synthesis has taken place. Objections 
have been raised to this work, and Cohnheim has held that 
the results noted by Glaessner may be due to differences in 
the case of coagulability of absolutely fresh protein of the 
mucous membrane, and of that which has been out of the 
body for some little time. Salaskin® offered as an explanation 
that the increase of protein may simply be due to a normal 
restitution of the cell protoplasm after its activity in ferment 
production. 
Reference may be here made to a change which has been 
declared by some to be a true resynthesis-—namely, to the for- 
mation of anhydride albumen, or plastein as it has been called. 
The curious property possessed by rennin of producing a 
precipitate—the plastein—in solutions of albumoses or pep- 
tones was first brought to notice by Okunew‘ in a Russian 
Glaessner, Ho/meister’s Beitrdge, 1, 1901, 320. 
Hofmeister, Schmiedeberg’s Archiv, 19, 1885, 1. 
Salaskin, Zett. f. physiol. Chem. 35, 1902, 419. 
Okunew (quoted by Sawjalow, Pfliiger’s Archiv, 85, 1901, 171). 
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