Quiz 4: Albumin

Question 1

Pre-albumin (Transthyretin)

Answer 1

• Migrates ahead of albumin in electrophoresis
• Transport protein for thyroid hormones and Vitamin A (retinol).
• Synthesized in liver and is a major indicator of nutritional status of the patient.

Question 2

Albumin Prevalence

Answer 2

• Synthesized in the Liver
• Albumin is the most abundant protein in the body.
• Most but not all urine protein is albumin

Question 3

Albumin Measurement

Answer 3

• Measured by dye-binding methods (bromcresol green; bromcresol purple etc)
• 3.9 - 5.1 g/dL (almost 50% of the total protein in serum)

Question 4

Functions of Albumin

Answer 4

• Control of colloid oncotic pressure (COP), the movement of water across membranes (high conc. of albumin maintains appropriate amount of fluid in tissues)
• Binding to substances in blood:
- carry hormones and drugs (bound vs. free)
- act as a buffer by binding free ions.

Question 5

Increased Serum Albumin Levels

Answer 5

Found only in dehydration

Question 6

Decreased Serum Albumin Levels

Answer 6

Found in a wide variety of conditions including:

(a) decreased synthesis in the liver
(b) hepatic disease (c) urinary loss
(d) malnutrition

Question 7

A/G Ratio Calculation and Ranges

Answer 7

• A measure of the ration between the two major forms of protein found in the serum, albumin and the globulins.
• Total Protein = Albumin + Globulins
• Total Protein - Albumin = Globulins
• TP = 6.4 - 8.3 g/dL
• Albumin = 3.9 - 5.1 g/dL

Question 8

Globulin Definition

Answer 8

• Second major category of proteins in serum.
• Consists of subgroups (based on their separation in electrophoresis) called:
alpha 1 and 2
beta 1 and 2
gamma fractions