Bilirubine

The bilirubine is a yellow pigment, whose abnormal accumulation in blood and fabrics determines a Ictère (or " jaundice "), which can concern very diverse causes. this pigment comes from the degradation of the Hémoglobine.

Hemoglobin consists of 4 hemes (prosthetic grouping) and of 4 globines (left proteinic). One distinguishes in the center from heme from the ferro-iron (Fe2+). At the time of the destruction of the red globules, hemoglobin which they contain is degraded; the heme being transformed into bilirubine.

The bilirubine integrates the bolus into the level of the small intestine, with the other biliary pigments. It is the principal pigment of deposit, person in charge of their yellowish color;

In the human organism, the rate of BNC (bilirubine not combined) is lower than 17 µmoles/l (10 mg/l).

Synthesis

The stages of the synthesis of the bilirubine are:
Heme → Biliverdine → bilirubine

The bilirubine which is produced is called the bilirubine " libre" or " not conjuguée".
Elle is introduced by the Macrophage S and passes in plasma, it joins a conveying protein: the Albumin which takes it along until the Foie. In the liver, the bilirubine will be combined with the Glucuronic acid (derivative of glucose).
On calls then it the combined bilirubine. It is soluble and not poison.
La bilirubine combined is then eliminated by the bile, one will then find it in the Small intestine where it will be degraded in Stercobiline (dark color brown) by the intestinal flora.

See too

Syndrome of Gilbert
Hépatologie

External bonds

Course hepatology of Necker on Bilirubine

Simple: Bilirubin

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