- Indirect faction – Biliary pigment. The indirect fraction is insoluble in water and can penetrate the cell membrane. This property explains the toxic effect. This fraction is synthesized in the reticuloendothelial system as a result of the enzymatic transformation of the gem formed during the decomposition of hemoglobin. After that, the substance binds to proteins, usually albumin, and is found in the liver.
- Direct (free) The fraction is formed in the liver by the combination with glucuronic acid. This reaction allows the pigment to acquire water-soluble properties, as well as to enter the duodenum, along with the bile. Other changes that bilirubin undergoes in the gastrointestinal tract. A small part returns to the blood, after which it is excreted in the urine after filtration in the kidneys. Basically, it, as a result, is transformed into esterkobilin, which is part of the stool and gives it a characteristic color.
- Total bilirubin in the biochemical analysis of blood: the result of adding the concentration of free and indirect fractions. The value of this indicator is the main guide for evaluating the bilirubin exchange, since it helps to establish the viability of determining the indicators of individual fractions. If total bilirubin is normal, additional investigation of bilirubin fractions is not appropriate. If this indicator increases, it is necessary to carefully study the individual fractions of a substance to determine the reasons for the increase in bilirubin levels.
How is bilirubin produced and derived?
Blood test for bilirubin
The biochemical analysis is performed on an empty stomach, the sample is taken from a vein. To get reliable results, you must give up alcohol and fatty foods for at least 24 hours.
The result is also affected by:
- The pregnancy
- Some medicines that affect the coagulation system (heparin, warfarin, aspirin)
- Excessive or strict diet.
- Choleretic herbs
- Drinks with caffeine.
Generally, in the following cases a blood test is performed to determine the bilirubin indicator:
- If symptoms of jaundice occur (this also applies to newborns)
- To diagnose liver function in cirrhosis, tumors, hepatitis.
- In the presence of pancreatitis or gallstone disease.
- In case of poisoning and various toxic effects.
- With the development of hemolytic disease.
- As a control of the effectiveness of the therapy.
Evaluating the exchange state of bilirubin allows biochemical analysis. Defines indicators of total bilirubin, direct (free) and indirect.