Bilirubin

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Bilirubin

The predominant orange pigment of bile. It is the major metabolic breakdown product of heme, the prosthetic group of hemoglobin in red blood cells, and other chromoproteins such as myoglobin, cytochrome, and catalase. The breakdown of hemoglobin from the old red cells takes place at a rapid rate in the reticuloendothelial cells of the liver, spleen, and bone marrow. The steps in this breakdown process include denaturation and removal of the protein globin, oxidation and opening of the tetrapyrrole ring, and the removal of iron to form the green pigment biliverdin, which is then reduced to bilirubin by the addition of hydrogen. The formed bilirubin is transported to the liver, probably bound to albumin, where it is conjugated into water-soluble mono- and diglucuronides and to a lesser extent with sulfate. See Liver

In mammalian bile essentially all of the bilirubin is present as a glucuronide conjugate. Bilirubin glucuronide is passed through the liver cells into the bile caniculi and then into the intestine. The bacterial flora further reduces the bilirubin to colorless urobilinogen. Most of the urobilinogen is either reduced to stercobilinogen or oxidized to urobilin. These two compounds are then converted to stercobilin, which is excreted in the feces and gives the stool its brown color. See Hemoglobin

Bilirubin

 

C33H36O6N4, a bile pigment; molecular mass 584.68. Brown crystals. Bilirubin is an intermediate product of the decomposition of hemoglobin that takes place in the macrophages of the spleen, liver, and bone marrow. It is formed by the enzymatic reduction of biliverdin. It is present in small quantities in the plasma of vertebrate animals and man (0.2–1.4 mg percent in a healthy person). When the outflow of bile is made difficult (obstruction of the bile ducts), and in some liver diseases, the bilirubin concentration increases in the blood (causing jaundice), and it appears in the urine. Hence, the presence of bilirubin in blood or urine is a diagnostic test.

bilirubin

[‚bil·ə′rü·bən]
(biochemistry)
C33H36N4O6 An orange, crystalline pigment occurring in bile; the major metabolic breakdown product of heme.
References in periodicals archive ?
Assessment of the fundamental accuracy of the Jendrassik-Grof total and direct bilirubin assays.
Conjugated bilirubin: a better indicator of impaired hepatobiliary excretion than direct bilirubin.
The two groups were compared in terms of average white blood cell count, platelet count, hemoglobin level, and serum AST, ALT, GGT, total bilirubin, direct bilirubin, PT/PIT and INR levels, and no relevant differences were found.
Our CARESIDE Analyzer, already the most comprehensive blood testing system cleared for point of care use, is the only blood diagnostic system that can provide the healthcare practitioner a rapid Direct Bilirubin test result in under 15 minutes.
The Direct Bilirubin test measures the concentration of Direct Bilirubin in anti-coagulated blood, plasma, and serum.
Direct bilirubin has been found to be negatively associated with PFOA concentrations in a few occupational studies (Costa a al.
7) (12,9) Direct bilirubin (mg/dl) Median /mean [+ 0.
The models were refit controlling for baseline factors: age, gender, dark urine, AST, ALT, indirect bilirubin, direct bilirubin, scleral icterus, and type of hepatitis (acute, chronic, undiagnosed source).
26 mmol/L Albumin (S), g/L 35-50 29 31 Total bilirubin (S), 2-26 66 136 mmol/L Direct bilirubin (S), <7 35 62 [micro]mol/L ALP (S), U/L 51-117 13 <5 [gamma]-Glutamyltransferase (S), <44 175 165 U/L AST (S), U/L 13-35 136 166 ALT (S), U/L <35 25 24 Lactate dehydrogenase (S), 120-230 786 U/L Haptoglobin (S), mg/L 300-2000 Hemoglobin, g/L 124-167 85 Total copper (S), 12.
I have reported, for instance, a case in which an unknown inhibitor caused the total bilirubin to be lower than the direct bilirubin.
The nine new product clearances for use on Roche's Cobas Mira are, Total Bilirubin, Magnesium, Creatinine, Phosphorus, Triglycerides - GPO, AST, Uric Acid, Direct Bilirubin
Anti a-b,total and direct bilirubin,creatinine liquicolor,glucose liquicolor,minidil etc.