Liver function test Flashcards
References: Book ni Dean Rodriguez sa CC Trans ni Rovie Vila sa CC
- It is the chief metabolic organ in the body
- Receives 15 mL of blood per minute
- It has the capacity to regenerate by cell division
- Liver is the largest internal organ
Liver
2 types of cells in liver
- Hepatocytes
- Kupfer cells
a phenomenon in which a drug gets metabolized at a specific location in the body that results in a reduced concentration of the active drug upon reaching its site of action or the systemic circulation
first pass phenomenon
Functions of the liver
1) Synthetic function
2) Conjugation function
3) Detoxification and Drug Metabolism
4) Excretory and Secretory Function
5) Storage Function
Conjugated with the amino acids glycine and taurine forming bile salts
Bile acids
It is stored in liver and released when glucose is depleted
Glycogen
Four general structures of proteins
a) Primary structure
b) Secondary structure
c) Tertiary structure - 1 polypeptide chain
d) Quaternary structure - 2 or more polypeptide chain
It provide the most useful indices for assessing severity of liver disease
- Serum albumin
- Vit. K dependent coagulation factors
Important for assessing nutritional status presence of severe diseases involving the liver, kidney and bone marrow
Protein
Plasma level of total protein
0.2-0.4 g/dL higher than serum due to fibrinogen
Ref. value of total protein
6.5-8.3 g/dL
In hydrolysis, It yield to amino acids
Simple Proteins
Example of Simple Proteins
1) Fibrous:
- fibrinogen, troponin
2) Globular:
-Hb, plasma proteins
3) Metalloproteins:
- ferritin, ceruloplasmin
Proteins with additional nonprotein moiety (prosthetic group)
Conjugated Proteins
Example of Conjugated proteins
1) Lipoproteins:
- CM, VLDL, LDL, HDL
2) Glycoproteins:
- haptoglobin, AAT
3) Mucoproteins:
- mucin
4) Nucleoproteins:
- chromatin
- Standard reference method
- Based on measurement of nitrogen content
- Used Serum + Tungstic acid => PFF
Kjeldahl (Digestion) method
1g Nitrogen =
6.54 grams of proteins
Nitrogen content of proteins
15.1-16.8%
Reagent of Kjeldahl (Digestion) method
H2SO4 (Sulfuric acid)
End product of Kjeldahl (Digestion) method
NH4 (ammonia)
- Most widely used method (IFCC recommended)
- Requires at least 2 peptide bond and an alkaline medium
Biuret method
Reagent used in Biuret method
- Alkaline CuSO4
- Rochelle salt (NaK tartrate)
- NAOH
- KI
Principle in Biuret method
Cupric ion complex the group involved in the peptide bond forming a violet-colored chelate which is proportional to the number of peptide bonds present and reflects the total protein level at 545 nm
End product of Biuret method
Violet color (545nm)
- Highest analytical sensitivity
- Oxidation of phenolic compounds (tyrosine, tryptophan and histidine)
Folin Ciocalteu (Lowry)
Reagents used in Folin Ciocalteu (Lowry)
- Phenol (or phosphotungstic-molybdic acid)
- Biuret (color enhancer)
End product of Folin Ciocalteu (Lowry)
deep Blue color
- Method in total proteins that absorb light at 280 nm and 210 nm
- absorption of 280 nm is due to tryptophan, tyrosine and phenylalanine
- absorption of 210 nm is due to absorbance of the peptide bonds
UV Absorption Method
- Alternative test
- Measurement of RI of solutes in serum
Refractometry
Formation of a uniform fine precipitate which block light
Turbidimetry
Reagents used in Turbidimetry
Sulfosalicylic acid (SSA) or Trichloroacetic acid (TCA)
Formation of a uniform fine precipitate which scatters light
Nephelometric Methods
Reagents used in Nephelometric
Sulfosalicylic acid (SSA) or Trichloroacetic acid (TCA)
- Globulins are separated from albumin by salting-out (Salt analysis) procedures using sodium salts
Salt fractionation
Salt used for analysis in Sodium sulfate
Sodium sulfate
Causes fo increased total protein
1) Malignancy
2) Multiple myeloma
3) Waldenstrom’s macroglobinemia
Causes fo decreased total protein
1) Hepatic cirrhosis
2) Glomerulonephritis
3) Nephrotic syndrome
4) Starvation
Differentiates intrahepatic from extrahepatic liver disease
Prothrombin Time
Vitamin K dependent factors
X, IX, VII, II (1972 - mnemonix), Protein C, Protein S
Administration of Vitamin K intramuscularly
10 mg daily for 1-3 days
- Transport and Oncotic pressure
- levels of protein in plasma decline when severe heaptocellular disease last more than 3 weeks
- inversely proportional to the severity of the liver disease
Albumin
Low total protein + low albumin =
Hepatic cirrhosis
What is the level of serum albumin?
- Severe dehydration
- Prolonged tourniquet application
Hyperalbuminuria
What is the level of serum albumin?
1. Reduced Synthesis
- Chronic liver disease (CLD) - Malabsorption syndrome
- Malnutrition and muscle wasting
- Increased loss
- Nephrotic syndrome
- Massive burns
- Protein-losing enteropathy
- Orthostatic proteinuria - Increased catabolism
- Massive burns
- Widespread malignancy
- Thyrotoxicosis - Inflammation
Hypoalbuminuria
total caloric deficiency
Marasmus
protein deficiency
Kwashiorkor
