Plasma Proteins

Question 1

Things that change albumin level

Answer 1

1. Overhydration
2. Protein losing enteropathy
3. Nephrotic syndrome
4. Malnutrition

Question 2

Methods to detect PP changes

Answer 2

1. Zonal electrophoresis
2. Ultracentrifuge methods
3. Immunochemical methods
4. Chemical methods

Question 3

PP changes in liver disease

Answer 3

1. Serum albumin ↓
2. Serum transferrin ↓
3. Serum globulin ↑

Question 4

Types of zonal electrophoresis

Answer 4

1. Gel electrophoresis
2. Paper electrophoresis
3. Capillary electrophoresis

Question 5

How does Albumin prevent Oedema?

Answer 5

1. Albumin is most abundant pp synthesized by liver (smallest)
2. Oedema is presence of excessive fluid in the extracellular compartment
3. Fluid filtration across capillaries is determined by hydrostatic & osmotic pressure of capillaries and IF
4. 80% of colloid osmotic pressure is done by albumin
5. Albumin maintains water content of interstitial fluid & normal blood volume
6. } Important in osmotic regulation to prevent oedema

Question 6

Transport of Calcium by Albumin

Answer 6

1. Albumin binds & transports FAs, bilirubin, calcium & many drugs
2. Albumin is water soluble to can easily transport molecules in the blood
3. In kidney disease, albumin loss can occur through the kidney (as it is smallest in size)
4. So there is albumin deficiency & calcium doesn’t have enough albumin to bind. So plasma calcium↑

Question 7

How does Pre Albumin work as a marker of malnutrition?

Answer 7

1. Prealbumin (transthyretin) is a pp that transports thyroid hormone
2. Has a 1/2 life of 2 days (albumin = 20 days)
3. Made by essential and non essential AAs
4. So it is more sensitive to changes in the protein energy status
5. In malnutrition, prealbumin is ↓ as it can’t be synthesized due to lack of nutrition; and already formed prealbumin is destroyed in 2 days
6. Due to its short 1/2 life, it reflects the recent dietary intake
7. Prealbumin is not affected by intestinal protein losing enteropathy so it is a better marker of malnutrition

Question 8

Electrophoresis

Answer 8

Definition:
1. Separation or movement of charged particles through a gel/solution under the influence of an electric field.
2. According to their charge, molecular weight & shape (usually used in separating plasma proteins)

Steps:
1. Introduce serum sample to acetate paper
2. Paper connected to buffer solution by using blotting paper strips on either end
3. System connected to E.F and wait 45 minutes
4. Dip cellulose acetate paper in dye to stain & wash in trichloroacetic acid to remove excess
5. Obtain electrophotogram which appears in bands distributed at - and + ends
6. Pass through densitometer to get densitogram
8. Bands represented as peaks according to absorbance, fluorescence & optical density of each PP