1. 275 BCH Miss Tahani Al-Shehri
Bilirubin & Jaundice
275 BCH
Miss Tahani Al-Shehri

2. Objective The aim of the experiment is to determine : Total bilirubin
Direct bilirubin
Indirect bilirubin , Contents of human serum .

3. Introduction
The liver responsible for many important metabolic functions
> 100 lab tests associated with liver function
Major hepatic functions
Protein synthesis
Regulation of carbohydrate metabolism
Regulation of lipoproteins
Detoxification of drugs and chemicals
Excretion of bile
Formation of bilirubin

4. Introduction Alkaline phosphatase SGOT ( AST) SGPT ( ALT)
These enzymes are released from dameged liver cells

5. Extravascular Pathway for RBC Destruction
(Liver, Bone marrow,
& Spleen)
Phagocytosis & Lysis
Hemoglobin
Globin
Heme
Bilirubin
Amino acids
Fe2+
Amino acid pool
Recycled
Excreted

6. DEGRADATION OF HEME TO BILIRUBIN
Bilirubin is the main pigment derived from heme catabolism
75% is derived from RBCs
In normal adults this results in a daily load of 200 mg of bilirubin
Normal plasma concentrations are less then 1 mg/dL
Hydrophobic – transported by albumin to the liver for further metabolism prior to its excretion
P450 cytochrome
“unconjugated” bilirubin

7. Unconjugated bilirubin Reticuloendothelial system
Heme
Biliverdin
Unconjugated bilirubin
Reticuloendothelial system
Unconj.bilirubin/albumin complex
Systemic circulation
Hepatocytes
Unconj. bilirubin
Bilirubin diglucuronide
Small intestine
Large intestine
Bilirubin
Urobilinogen
Stercobilins
Kidney
urine

8. HYPERBILIRUBINEMIA
-- elevated bilirubin in serum (above 3mg/dL) occur when there is imbalance between production and excretion
-- can be conjugated or unconjugated or both depending on the situation
-- elevated bilirubin can diffuse into tissues, making them appear yellow (jaundice)

9. Clinical Consequences:
HYPERBILIRUBINEMIA
Clinical Consequences:
-- Conjugated hyperbilirubinemia: benign
-- Unconjugated hyperbilirubinemia: benign at concentrations < 25 mg/dL (albumin capacity)
-- At concentrations >25 mg/dL, unconjugated bilirubin is free (uncomplexed) and can enter the brain.
bilirubin encephalopathy (kernicterus)

10. Causes of JAUNDICE
( per-hepatic_ the pathology is occurring prior to the liver ) Ex. Hemolytic anemia
--  destruction of erythrocytes
( hepatic _ the pathologyis located within the liver ) a)Hepatitis b) cirrhosis
--  conjugation and excretion of bilirubin
c) Neonatal “physiological jaundice”
-- immature hepatic system of the newborn:
 uptake, conjugation, excretion of bilirubin
3) ( post-hepatic _ _ the pathology is occurring poster to the liver ) Bile duct obstruction
-- conjugated bilirubin not delivered to intestine;
it backs up, spills over into the blood

11. principle Direct bilirubin water soluble Bilirubin + Diazo reagent
Red –blue color
* Only direct bilirubin react .

12. principle Direct bilirubin water soluble
Bilirubin + Diazo reagent + caffeine
Red –blue color
Direct + indirect bilirubin react .

13. Total bilirubin = Conjugated + Un conjugated Bilirubin.