bilirubiinidiglukuronidi

Bilirubiinidiglukuronidi, or bilirubin diglucuronide, is the conjugated form of bilirubin produced in the liver. It forms when bilirubin, derived from heme breakdown, is enzymatically linked to two glucuronic acid molecules by UDP-glucuronosyltransferase enzymes. This conjugation increases bilirubin’s water solubility, allowing it to be excreted into bile.

In the liver, unconjugated bilirubin is taken up by hepatocytes and glucuronidated to direct, or conjugated, bilirubin. The conjugated bilirubin is transported into the bile canaliculi and released into the biliary system, eventually reaching the intestine. In the gut, bacterial enzymes deconjugate bilirubin diglucuronide, generating bilirubin and other breakdown products that contribute to stool color. Some conjugated bilirubin can be reabsorbed into the circulation and, if present in excess, may be detected in urine as direct bilirubin.

Clinically, the measurement of direct (conjugated) bilirubin helps distinguish types of hyperbilirubinemia. Elevated bilirubin diglucuronide indicates disorders affecting bile formation or flow, such as cholestasis or biliary obstruction, or significant hepatocellular dysfunction. In healthy individuals, most bilirubin is excreted via bile; only small amounts appear in urine under normal conditions.

The concept of bilirubin conjugation, including bilirubiinidiglukuronidi, is central to understanding jaundice, liver function tests, and the differential diagnosis of hyperbilirubinemia.