Full resolution (JPEG) - On this page / på denna sida - X. The Muscles - Extractive Bodies of the Muscles
<< 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.
CREATINE. 573
p. m. and 0.71 p. m. respectively, which corresponds closely to the results found
by Scaffidi, Buglia and Costantino for the striated muscle of the calf, namely,
().">s Of is p. in. According to Hinaldi and Scaffidi ’
the lowest values for the
purine nitrogen occur in the striated muscles of the covering of polype, 0.436
p. m., then in fishes 0.595-0.82 p. m. and the highest L.061 p. in. in birds. Bi QUA
and Costantino have determined the nitrogen titcatable with formol, and from
this determined the amount of monamino-acid nitrogen as well as diamino-acid
nitrogen in various animals. In oxen they found in the moist, striated muscle
0.18 p. in. inonamino- and 0.40 p. m. diamino-nitrogen. In the heart the cor-
responding figures were 0.18 and 0.18 p. m. In percentage of the total nitrogen
the total amino-acid nitrogen in the striated muscle was 1.70 per cent and in
the heart 1.48 per cent.
The most extensively occurring nitrogenous extractives in the muscle
are creatine and carnosine.
(
/NH2
Creatine, C4H9N3O2, C=NH , or methyl-guanidine-
\N(CH3 ).CH2COOH
acetic acid, occurs in the striated as well as smooth muscles. In the
striated muscle of vertebrates the amount varies between 2.5 and 7 p. m.
It is also found in the brain, blood, transudates, amniotic fluid, and
sometimes also in the urine.
Creatine may be prepared synthetically from cyanamide and sar-
cosine (methylglycocoll). On boiling with baryta-water it decomposes,
with the addition of water, and yields urea, sarcosine, and certain other
products. Because of this behavior several investigators consider
creatine as a step in the formation of urea in the organism. On boiling
with acids, creatine is easily converted, with the elimination of water
into the corresponding anhydride, creatinine, C4H7N3O, which is retrans-
formed into creatine by the action of alkali.
The question as to the mutual relation of creatine to creatinine in
metabolism will be treated in Chapter XIV (urine). In this chapter,
besides the properties and reactions, we will discuss the question as to
the origin of creatine and its relation to the metabolism of the muscles.
Of special interest in this regard, besides the relation between creatine
and muscle work which will be discussed below, is the question as to
the occurrence of free or combined creatine in the muscle. Urano by
the aid of dialysis experiments has shown the probability that the crea-
tine does not exist free in the muscle, but as a labile, non-dialyzable
combination. Nevertheless Gottlieb and Stangassinger claim by
various researches to have shown in the autolysis of muscles and other
organs,.that.creatine is first formed and then first changed into creatinine
by special bodies of an enzymotic nature, and then destroyed. Seemann
1
v. Furth and Schwarz, Bioch. Zetschr., 30; Scaffidi, ibid., 33; Burian and Hall,
Zeitschr. f. physiol. Chem. 38; Buglia and Costantino, ibid., 81 and 82; Rinaldi and
Scaffidi, Bioch. Zeitschr., 41.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
