Urobilinogen

Urobilinogen

Chembox new
ImageFile=Urobilinogen.pngImageSize=
IUPACName=
OtherNames=
Section1= Chembox Identifiers
CASNo=14684-37-8
PubChem=26818
SMILES=
MeSHName=Urobilinogen

Section2= Chembox Properties
Formula=C33H44N4O6
MolarMass=592.726
Appearance=
Density=
MeltingPt=
BoilingPt=
Solubility=

Section3= Chembox Hazards
MainHazards=
FlashPt=
Autoignition=

Urobilinogen is a colourless product of bilirubin reduction. It is formed in the intestines by bacterial action. Some urobilinogen is reabsorbed, taken up into the circulation and excreted by the kidney. This constitutes the normal "intrahepatic urobilinogen cycle".

Increased amounts of bilirubin are formed in haemolysis which generate increased urobilinogen in the gut. In liver disease (such as hepatitis) the intrahepatic urobilinogen cycle is inhibited also increasing urobilinogen levels. Urobilinogen is converted to the yellow pigmented urobilin apparent in urine.

The urobilinogen remaining in the intestine (stercobilinogen) is oxidized to brown stercobilin which gives the feces their characteristic color.

In biliary obstruction, below normal amounts of conjugated bilirubin reach the intestine for conversion to urobilinogen. With limited urobilinogen available for reabsorption and excretion, the amount of urobilin found in the urine is low. High amounts of the soluble conjugated bilirubin enter the circulation where they are excreted via the kidneys. These mechanisms are responsible for the dark urine and pale stools observed in biliary obstruction.

Abnormal values

Absence of urine urobilinogen may result from complete obstructive jaundice or treatment with broad-spectrum antibiotics, which destroy the intestinal bacterial flora. (Failure of bilirubin production or obstruction of bilirubin passage.)

Low urine urobilinogen levels may result from congenital enzymatic jaundice (hyperbilirubinemia syndromes) or from treatment with drugs that acidify urine, such as ammonium chloride or ascorbic acid.

Elevated levels may indicate hemolytic jaundice, overburdening of the liver, excessive RBC breakdown, increased urobilinogen production, re-absorption - a large hematoma, restricted liver function, hepatic infection, poisoning or liver cirrhosis. [cite web | url = http://www.family-health-information.com/lab-tests/urobilinogen.htm | title = Urobilinogen | publisher = Family Health Information | accessdate = 2008-03-30] [cite web | url = http://www.anytestkits.com/utk-urobilinogen-in-urine.htm | title = Urobilinogen in urine | publisher = Home test kist | accessdate = 2008-03-30]

References

External links

* [http://www.expasy.ch/cgi-bin/show_image?L6&up Biochemicals pathways Map]


Wikimedia Foundation. 2010.

Игры ⚽ Нужен реферат?

Look at other dictionaries:

  • urobilinogen — UROBILINOGÉN, urobilinogene, s.n. Compus organic format în intestin prin reducerea bilirubinei, reabsorbit apoi numai în parte prin peretele intestinal şi redat ficatului. – Din fr. urobilinogène. Trimis de valeriu, 13.09.2007. Sursa: DEX 98 … …   Dicționar Român

  • Urobilinogen — Strukturformel in physiologischem Medium vorliegende Struktur Allgemeines Name …   Deutsch Wikipedia

  • urobilinogen — Precursor of urobilin. * * * uro·bi·lin·o·gen .yu̇r ə bī lin ə jən, .jen n any of several chromogens that are reduction products of bilirubin and yield urobilins on oxidation called also stercobilinogen * * * n. a colourless product of the… …   Medical dictionary

  • urobilinogen — n. a colourless product of the reduction of the bile pigment bilirubin. Urobilinogen is formed from bilirubin in the intestine by bacterial action. Part of it is reabsorbed and returned to the liver; part of it is excreted in the faeces (a trace… …   The new mediacal dictionary

  • urobilinogen — noun A colourless product of bilirubin reduction, formed in the intestines by bacterial action …   Wiktionary

  • Urobilinogen — Uro|bi|li|no|gen, das; s [↑ gen] (Med.): Vorstufe des Urobilins …   Universal-Lexikon

  • urobilinogen — u|ro|bi|li|no|gen Mot Pla Nom masculí …   Diccionari Català-Català

  • Urobilinogen — Uro|bilino|ge̱n [↑Urobilin u. ↑...gen] s; s: im Darm beim Abbau des ↑Hämoglobins entstehende farblose Vorstufe des ↑Urobilins …   Das Wörterbuch medizinischer Fachausdrücke

  • Urobilinogen — Uro|bi|li|no|gen das; s <zu ↑...gen> Vorstufe des Urobilins …   Das große Fremdwörterbuch

  • urobilinogen — uro·bi·lin·o·gen …   English syllables

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”