Full resolution (JPEG) - On this page / på denna sida - XIV. Urine - II. Organic Physiological Constituents of Urine
<< prev. page << föreg. sida << >> nästa sida >> next page >>
Below is the raw OCR text
from the above scanned image.
Do you see an error? Proofread the page now!
Här nedan syns maskintolkade texten från faksimilbilden ovan.
Ser du något fel? Korrekturläs sidan nu!
This page has never been proofread. / Denna sida har aldrig korrekturlästs.
CREATININE. 693
As the two bodies, creatine and creatinine, can easily be transformed
into each other, it has been considered for a long time that the urinary
creatinine is formed from the creatine of the muscles and other organs.
Unfortunately the authorities disagree on this question. Folin in his
investigations found that about 80 per cent of the creatinine intro-
duced was again eliminated, while the creatine taken did not appear in
the urine as creatinine, but was partly retained by the body and in
part eliminated, as such. An intravital transformation of creatine into
creatinine is disputed by v. Klercker, Mellanby and Lefmann,1
while
it is accepted by Gottlieb, Stangassinger, S. Weber, v. Hoogen-
huyze and Verploegh and Rothmann. The observations of Myers
and Fine indicate a production of urinary creatinine from creatine, that is
they found that the creatinine elimination by the urine in rabbits was
greater according to the total creatine content of the respective animal.
The investigations of Pekelharing and v. Hoogenhuyze on the behavior
of parenterally introduced creatine in rabbits and dogs, show without
any doubt that a part of the creatine is actually transformed into creatinine.
Towles and Voegtlin 2
have also observed that the subcutaneously
injected creatine increases somewhat the creatinine elimination, while this
is not the case with creatine taken per os. The condition of the digestive
apparatus also seems to be of importance here. Pekelharing and v.
Hoogenhuyze found that in dogs of the parenterally introduced creatine
always a smaller part (as creatine and creatinine) passed into the urine
during the digestion than during rest of the digestive organs. They
explain this by the accepted ability of the liver to partly destroy the
creatine and partly by an anhydride formation of transforming the creatine
into creatinine.
As mentioned in Chapter X the proteins and the guanidine groups
therein are considered as the mother-substance of these two bodies.
If the creatinine (creatine) originates from the protein it is evident that
we must differentiate between food-protein and body-protein. The quan-
tity of creatinine is, inasmuch as it is increased by meat diet, dependent
upon the food; but otherwise, as found by Folin and in chief substantiated
by others, is rather independent of the food. Its elimination does not
run parallel with the urea and the total nitrogen, and consequently is
not in general greater with food rich in protein than with food poor therein.
On the contrary, its extent, as shown by other conditions, is dependent
upon the intensity of the metabolism in the cells, especially the muscle
1
Folin, Hammarsten’s Festschrift, 1906; v. Klercker, Bioch. Zeitschr., 3; Mellanby,
Journ. of Physiol., 36; Lefmann, Zeitschr. f. physiol. Chem., 57.
2
See footnote 1, page 574, and v. Hoogenhuyze and Verploegh, Zeitschr. f. physiol.
Chem., 59; Pekelharing and v. Hoogenhuyze, ibid., 69; Towles and Voegtlin, Journ.
of biol. Chem., 10; Myers and Fine, ibid., 14.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
