bilirubin

bilirubin
A yellow bile pigment found as sodium bilirubinate (soluble), or as an insoluble calcium salt in gallstones; formed from hemoglobin during normal and abnormal destruction of erythrocytes by the reticuloendothelial system; a bilin with substituents on the 2, 3, 7, 8, 12, 13, 17, and 18 carbon atoms and with oxygens on carbons 1 and 19. Excess b. is associated with jaundice. [bili- + L. ruber, red]
- conjugated b. SYN: direct reacting b..
- delta b. the fraction of b. covalently bound to albumin; in conventional methods it is measured as part of conjugated b.. Because of its covalent bond during the recovery phase of hepatocellular jaundice it may persist in the blood for a week or more after urine clears.
- direct reacting b. the fraction of serum b. which has been conjugated with glucuronic acid in the liver cell to form b. diglucuronide; so called because it reacts directly with the Ehrlich diazo reagent; increased levels are found in hepatobiliary diseases, especially of the obstructive variety. SYN: conjugated b..
- indirect reacting b. the fraction of serum b. which has not been conjugated with glucuronic acid in the liver cell; so called because it reacts with the Ehrlich diazo reagent only when alcohol is added; increased levels are found in hepatic disease and hemolytic conditions. SYN: unconjugated b..
- b. UDPglucuronyltransferase (gloo-koo′ron-il-trans′fer-as) an enzyme that catalyzes the reaction of UDPglucuronate and b. forming UDP and b.-glucuronoside; a deficiency of this enzyme is associated with Crigler-Najjar syndrome.
- unconjugated b. SYN: indirect reacting b..

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bil·i·ru·bin .bil-i-'rü-bən, 'bil-i-. n a reddish yellow pigment C33H36N4O6 that occurs esp. in bile and blood and causes jaundice if accumulated in excess

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n.

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bil·i·ru·bin (bil″ĭ-rooґbin) [bili- + ruber] a yellow bile pigment that is a breakdown product of heme mainly formed from the degradation of erythrocyte hemoglobin in reticuloendothelial cells; it is also formed by breakdown of other heme pigments, such as cytochromes. Bilirubin normally circulates in plasma as a complex with albumin, and is taken up by the liver cells and conjugated to form water-soluble bilirubin diglucuronide for excretion in the bile. In patients with cholestasis, this latter form accumulates in the blood and tissues and is excreted in the urine. (Unconjugated bilirubin is not excreted in the urine.) High concentrations of bilirubin may result in jaundice. bilirubinic adj

Medical dictionary. 2011.

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Look at other dictionaries:

  • Bilirubin — Bilirubin …   Wikipedia

  • Bilirubin — (Gallenrot), ein rotbrauner Gallenfarbstoff (s. Galle) von der Zusammensetzung C16H18N2O3. Das Bilirubin ist ein lebhaft rotes Pulver, oder es erscheint kristallisiert in mikroskopischen, deutlich ausgebildeten rhombischen Tafeln. Es besitzt ein… …   Lexikon der gesamten Technik

  • bilirubin — reddish pigment found in bile, 1871, from Ger. bilirubin (1864), from bili (see BILE (Cf. bile)) + L. ruber red (see RED (Cf. red)) + INE (Cf. ine) (2) …   Etymology dictionary

  • bilirubin — bilirùbīn m <G bilirubína> DEFINICIJA biol. C33H36O6N4, narančastocrveni pigment u žuči sisavaca, nastaje razgradnjom hemoglobina u jetrima, kod oboljenja od žutice pojavljuje se u mokraći i krvi ETIMOLOGIJA njem. Bilirubin ≃ lat. bilis:… …   Hrvatski jezični portal

  • Bilirubin — Bil i*ru bin, n. [L. bilis biel + ruber red.] (Physiol.) A reddish yellow pigment present in human bile, and in that from carnivorous and herbivorous animals; the normal biliary pigment. [1913 Webster] …   The Collaborative International Dictionary of English

  • bilirubin — bilirubin. См. билирубин. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Bilirubīn — Bilirubīn, s. Galle …   Meyers Großes Konversations-Lexikon

  • Bilirubin — ⇒ Gallenfarbstoffe …   Deutsch wörterbuch der biologie

  • bilirubin — [bil΄i ro͞o′bin] n. [ModL < L bilis, bile + ruber,RED + IN1] the yellowish red chief pigment, C33H36N4O6, of human bile, derived from biliverdin and found in small quantities in blood and urine: high concentrations change the color of blood… …   English World dictionary

  • Bilirubin — Strukturformel deprotonierte Form des Bilirubins (unter physiologischen Bedingungen) Allgemeines …   Deutsch Wikipedia

  • bilirubin — /bil euh rooh bin, bil euh rooh bin/, n. Biochem. a reddish bile pigment, C33H36O6N4, resulting from the degradation of heme by reticuloendothelial cells in the liver: a high level in the blood produces the yellow skin symptomatic of jaundice. [… …   Universalium

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