CC1 - Liver Synthetic Function Flashcards
The chief metabolic organ
Liver
The liver is a large organ divided unequally into two lobes by
falciform ligament
2 major cell type of liver
Hepatocytes (80%)
Kupffer cells
Hepatic macrophage that acts as phagocytes. They also line the sinusoid of the liver.
Kupffer cells
They perform the major functions of the liver and also responsible for its regenerative functions
Hepatocytes
2 blood suppliers of the liver (1500 mL/min)
o Hepatic artery (25%)
o Portal Vein (75%)
Synthetic Function of liver
Ability of the liver to synthesized substance.
All proteins are synthesized in the liver except for immunoglobulins. Which are synthesized by the lymphocytes.
Conjugation Function of liver
Process in the metabolism of bilirubin
Detoxification and Drug Metabolism of liver
Your liver has the ability to protect you from potentially toxic substances absorbed from the
intestine and other toxic metabolic bi-product
Excretory and Secretory function of liver
Your liver is involved in the excretion of bile. Bile is involved in the elimination of cholesterol and o t her bi le salts.
Storage Function OF LIVER
Your liver serves as your storage for all your fat soluble an d some of the water soluble vitamins and also the storage site for glycogen (ex. of fat soluble Vitamin: A, D, E, K
It tests the validity of the liver to synthesized and quantitates the severity of hepatic dysfunction.
LIVER SYNTHETIC FUNCTION TEST
sum of albumin + globulin proteins
Total protein
Assessment of nutritional status and presence of severe disease involving the liver, kidney and bone marrow
Total protein
TOTAL PROTEIN
Sample :
Interference :
Reference value (serum):
Sample : Serum
Interference : hemolysis, ictericia
Reference value (serum): 6.5 8.3g/dL (CF to g/L:10)
Why is plasma not used in total protein?
plasma is not used in total protein because it has fibrinogen , and fibrinogen makes results falsely increased (0.2 0.4 g)
Methods for total protein:
Classical method for protein quantitation
This process is time consuming.
Reference method but not routinely used
Measures the amount of nitrogen in specimen.
Assumes that nitrogen content of protein is 16
(15.1 16. 8)
1g of nitro gen = 6.54g of protein
Kjeldahl Method
3 steps in Kjeldahl
o Digestion
o Distillation
o Titration
Methods for total protein
Principle: Measures protein based on the number of peptide bonds present.
Biuret Method
Methods for total protein
Most widely used method for total protein determination
Is a colorimetric non enzymatic method
Absorbance of color is read at 540 nm.
End color is: deep purple or violet , non-enzymatic
because this does not utilized enzymes
Biuret reagent has : Alkaline CuSO4 , NaK tartrate (Rochelle salt prevents precipitation of copper NaOH , KI (stabilizer)
Interferences in biuret method is lipemic sample
Biuret Method
Methods for total protein:
Principle : Oxidation of phenolic compounds such as tyrosine, tryptophan, and histidine to give a deep blue color
Folin Ciocalteu (Lowry) method
Has t he highest analytical sensitivity
It can measure very minute amount or concentration of protein
Main reagent : Phosphotungstic molybdic acid or phenol reagent
Color enhancer : Biuret reagent
Folin Ciocalteu (Lowry) method
Principle : The absorbance of proteins at 210nm is
due to the absorbance of the peptide bonds at
specific wavelength.
Absorptions at 280nm: tryptophan, tyrosine, and
phenylalanine
UV absorption method
Based on measurements of refractive index of
serum total proteins
Refractometry
Measurement depends on formation of a uniform
fine precipitate which scatters incident light in
suspension (nephelometry) or block light (turbidimetry)
Turbidimetry and Nephelometry Methods
Used for detection of proteins as little as 1 ug
Coomasie Brilliant blue Dye
Develops violet color by reacting with primary
a mines widely used for detection of peptides and
amino acids after paper chromatography.
Ninhydrin
Principle : migration of charged particles in an
electric field
Negative electrode : cathode and positive electrode : anode
Serum protein electrophoresis
Isoelectric property of proteins
Amphoteric - either positive or negative depending on pH condition
No charge at isoelectric point
The acidic and basic amino acid content of proteins determines its net charge.
Buffer : barbital (Veron al) pH 8.6
Albumin band (1st band)
a. Reference value: 3.5 5.0g/ dL ( 5 3 65%)
b. Fastest band, most anodal
c. Nearest to the positive
A1 globulin band
a. Reference value: 0.1 0.3g dL ( 2. 5 5%)
b. Second fastest and second most anodal
c. Alpha 1 antitrypsin (AAT)
Alpha globulin band
a. Reference value: 0.6 1.0 g/dL (7 13%)
B globulin band
a. Reference value: 0.7 1.1g/d l (8 14%)
Y globulin band
a. Reference value: 0 .8 1.6 g/dL (12 22%)
b. This includes immunoglobulin
Most abundant among proteins
Concentration is directly proportional to the severity of hepatic disease
Low levels could be caused by decreased synthesis
Albumin
Albumin reference value
3.5 5.0 g /dL
The liver synthesizes how many grams of albumin per day?
9-12 g
Methods of Albumin
o Salt precipitation
o Dye binding
What is precipitated in Albumin salt precipitation?
GLobulins
Most commonly used dye in albumin dye binding method
Bromcresol green (BCG)
Most specific dye in albumin dye binding method
Bromcresol purple (BCP)
Dye not specific for albumin
Methyl orange
Inverted Albumin/Globulin ratio can be seen in
cirrhosis, multiple myeloma , & Waldenstroms macroglobulinemia
Albumin globulin ratio Reference value:
1.3 3.1g/dL (C F to G/L:10)
Albumin globulin ratio formula
AG ratio = albumin /globulin
Globulin value is determined using the formula
Globulin = total protein - albumin
Vitamin K response Test
Prothrombin Time
Vitamin K dependent clotting factors:
prothrombin group Factor 2, 7,9,10
Normal PT after administering Vit K
it means it extrahepatic.
In Vitamin K response test if prothrombin time is prolonged, this indicates
that you have problem in the
hepatic
It differentiates intrahepatic disorders from extrahepatic disorder
Prothrombin Time
Prolonged PT
signifies massive cellular damage
