Breakdown product of haem. Sources of haem include haemoglobin from senescent red blood cells, myoglobin and cytochrome enzymes.
|The terminology direct and indirect derive from the way they react with certain chemical dyes. Water-soluble, conjugated bilirubin reacts directly, whereas unconjugated bilirubin requires alcohol treatment before it reacts with the dye (i.e. an indirect reaction). Conjugated and unconjugated are more explicit and are the preferred terms.|
Bilirubin is found in two forms: conjugated (direct) and conjugated (indirect). Tbound to albumin in plasma. Unconjugated Bilirubin is eliminated from the body by conjugating it with a glucuronyl residue, which renders it water soluble, allowing renal excretion. The process of takes place in the liver and requires the enzyme glucuronyl transferase.
Hyperbilirubinaemia is known more commonly as jaundice.