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.
740 URINE.
wise, in regard to its behavior with alkalies, with access of air, and also with
alkaline copper solutions and ammoniacal silver solutions, and also Millon’s
reagent, it is similar to homogentisic acid.
Neubaueb and Flatow, who have prepared dioxyphenyl-a-lactic acid syn-
thetically, find that this acid has entirely different properties from the so-called
uroleucic acid. Garrod and Hurtley ’ have also shown that an impure homo-
gentisic acid with a low melting-point is easily obtained, and they suggest the
possibility that the earlier reports in regard to uroleucic acid are due to an error.
CH COH
HC C C.COOH
Kynurenicacid(y-ox}’-/3-quinohncarboxvhcacid),CioH7N03,
HC C CH
CH N
has only been found thus far in dog’s urine, but not always; its quantity is increased
by meat feeding. It does not occur in the urine of cats. Ellinger 2
has been
able to show positively that tryptophane is the mother-substance of this acid.
By the introduction of tryptophane in the organism he has shown the formation
of a kynurenic acid not only in dogs but also in rabbits.
The acid is crystalline, does not dissolve in cold water, rather well in hot alcohol,
and yields a barium salt which crystallizes in triangular, colorless plates. On
heating it melts and decomposes into C02 and kynurin. On evaporation to dry-
ness on the water-bath with hydrochloric acid and potassium chlorate a reddish
residue is obtained which on adding ammonia becomes first brownish green and
then emerald green (Jaffe’s reaction 3
).
Urinary Pigments and Chromogens. The yellow color of normal
urine depends perhaps upon several pigments, but in greatest part upon
urochrome. Besides this the urine seems to contain a very small quantity
of hoematoporphyrin as a regular constituent. Uroerythrin is also of
frequent occurrence in normal urine, but not always. Finally, the
excreted urine when exposed to the action of light regularly contains a
yellow pigment, urobilin, which is derived from a chromogen, urobilinogen,
by the action of light (Saillet) and air (Jaffe, Disque 4
) and others.
Besides this chromogen, urine contains various other bodies from which color-
ing matters may be produced by the action of chemical agents. Humin sub-
stances (perhaps in part from the carbohydrates of the urine) may be formed
by the action of acids (v. Udranszky) without regard to the fact that such sub-
stances may sometimes originate from the reagents used, as from impure amyl
1
Journ. of Physiol., 30.
*Ellinger, Ber. d. d. chem. Gesellsch., 37, 1804, and Zeitschr. f. physiol. Chem.,
43. The older literature on kynurenic acid may be found in Josephsohn, Beitrage zur
Kenntnis der Kynurensaure ausscheidung beim Hunde, Inaug. -Dissert., Konigsberg,
1898.
’ Zeitschr. f. physiol. Chem., 7. In regard to kynurenic acid, see also Huppert-
Neubauer, 10. Aufl., and Mendel and Jackson, Amer. Journ. of Physiol., 2; Mendel
and Schneider, ibid., 5; Camps, Zeitschr. f. physiol. Chem., 33.
4
Jaffp, Centralbl. f. d. med. Wissensch., 1896 and 1869, and Virchow’s Arch., 47;
Disque, Zeitschr. f. physiol. Chem., 2; Saillet, Revue de medecine, 17, 1897.
<< prev. page << föreg. sida << >> nästa sida >> next page >>
