Bilirubin exists in two forms, which are the
unconjugated and conjugated bilirubin.
unconjugated and conjugated bilirubin.
Unconjugated bilirubin: Unconjugated bilirubin is also known as indirect bilirubin. The haem
(iron porphyrin) of the haemoglobin molecule is firstly removed from the
globin. The porphyrin portion is then converted to biliverdin which is reduced
to bilirubin. The bilirubin is insoluble in water, it is carried in the blood
attached to albumin and it cannot be excreted by the kidney. This bilirubin is
referred to as unconjugated or indirect bilirubin (Ochei & Kolhatkar,
2007).
(iron porphyrin) of the haemoglobin molecule is firstly removed from the
globin. The porphyrin portion is then converted to biliverdin which is reduced
to bilirubin. The bilirubin is insoluble in water, it is carried in the blood
attached to albumin and it cannot be excreted by the kidney. This bilirubin is
referred to as unconjugated or indirect bilirubin (Ochei & Kolhatkar,
2007).
Conjugated bilirubin: In the liver, bilirubin combines with glucuronic acid by the enzyme
glucuronyltranferase, making is soluble in water; the conjugated vision is
often called “direct” bilirubin. Much of it goes into the small intestine.
Though most bile acid is resorted in the terminal ileum to participate in
enterohepatic circulation, conjugated bilirubin is not absorbed and instead passes
into the colon. Total bilirubin comprises of both conjugated and unconjugated,
total bilirubin and conjugated bilirubin levels are measured directly in the
blood, whereas indirect bilirubin level are derived from the total and direct
bilirubin measurement (Cheifetz & Adam, 2010).
glucuronyltranferase, making is soluble in water; the conjugated vision is
often called “direct” bilirubin. Much of it goes into the small intestine.
Though most bile acid is resorted in the terminal ileum to participate in
enterohepatic circulation, conjugated bilirubin is not absorbed and instead passes
into the colon. Total bilirubin comprises of both conjugated and unconjugated,
total bilirubin and conjugated bilirubin levels are measured directly in the
blood, whereas indirect bilirubin level are derived from the total and direct
bilirubin measurement (Cheifetz & Adam, 2010).
References
Cheifetz,
A. & Adam, S. (2010): Oxford American
handbook of gastroenterology and hepatology. Oxford: Oxford University
Press, USA. pp165.
A. & Adam, S. (2010): Oxford American
handbook of gastroenterology and hepatology. Oxford: Oxford University
Press, USA. pp165.
Ochei,
J. & Kolhatkar, A. (2007): Medical laboratory
science theory and practical. Tata MacGraw Hill Publishing Company
J. & Kolhatkar, A. (2007): Medical laboratory
science theory and practical. Tata MacGraw Hill Publishing Company
