Liver Function and Serum Proteins Quiz

Questions and Answers

How do prothrombin time and serum albumin levels change in liver failure?

Serum albumin decreases and prothrombin time becomes prolonged in liver failure.

What conditions could lead to elevated levels of SGOT/AST?

Elevated levels of SGOT/AST can result from myocardial infarction, viral hepatitis, liver necrosis, cirrhosis, and muscular dystrophy.

What is the significance of the factor factor in the AST/GOT calculation?

The factor is a variable used in the AST/GOT ratio calculation for accurate concentrations, primarily set at 1745.

What is the relationship between ALT/SGPT levels and liver disease?

Increased ALT/SGPT levels generally indicate liver disease associated with necrosis, such as cirrhosis or viral hepatitis. Signup and view all the answers

How can the concentration of AST/SGOT be converted from U/L to ukat/L?

The conversion can be done by multiplying the U/L value by 0.017 to obtain ukat/L. Signup and view all the answers

What role does LDH play in diagnosing liver-related conditions?

High levels of LDH (≥ 4000 U/l) can indicate tissue damage, including that related to liver conditions. Signup and view all the answers

Why is it important to maintain reagent stability in enzyme assays?

Reagent stability ensures accurate and reliable results over time for diagnostic testing. Signup and view all the answers

What differentiates ALT/SGPT from AST/SGOT in terms of liver disease specificity?

ALT/SGPT is more liver-specific, usually showing higher levels than AST/SGOT in acute liver diseases. Signup and view all the answers

How does the distribution of AST differ from ALT in the body?

AST is widely distributed in various tissues, while ALT is primarily found in high concentrations in the liver. Signup and view all the answers

What are the implications of changing the K-factor when using reagents from different manufacturers?

Changing the K-factor is necessary to ensure accurate enzyme concentration calculations based on reagent specifications. Signup and view all the answers

Study Notes

Liver Function and Coagulation Factors

Major proteins in plasma synthesized by the liver from amino acids include serine protease coagulation factors, prothrombin, and serum albumin.
Prothrombin time and serum albumin levels are indicators of liver function; decreased albumin and prolonged prothrombin time signify liver failure.

Enzymes and Tissue Distribution

SGOT (AST) is widely distributed across heart, liver, skeletal muscle, kidney, and erythrocytes.
Elevated SGOT/AST levels can indicate tissue damage or diseases such as myocardial infarction, viral hepatitis, liver necrosis, cirrhosis, or muscular dystrophy.

Reagent Composition

R1 consists of Tris Buffer (pH 7.8) at 110 mmol/l and L-Aspartate at 340 mmol/l.
R2 contains LDH ≥ 4000 U/l and MDH ≥ 750 U/l, with CAPSO at 20 mmol/l and 2-Oxoglutarate at 85 mmol/l.
Mix reagent R1 (4 portions) with reagent R2 (1 portion) in a 4:1 ratio.

Stability of Reagents

Reagents remain stable for 5 days at 20–25 °C in the dark and for 4 weeks at 2–8 °C in dark conditions.

AST/GOT Calculation

AST/GOT concentration is calculated using the formula: AST/GOT = f x ΔA/min, where f is the factor, typically around 1745.
K-factor varies based on the manufacturer; e.g., Erba (1745) and AGAPE (1746).
AST/SGOT is measured in Unit/Litre (U/L), convertible to ukat/L using the formula: U/L × 0.017 = ukat/L, applicable to ALT/SGPT as well.

ALT/SGPT Clinical Significance

ALT/SGPT is predominantly found in the liver but also in kidney, heart, skeletal muscles, pancreas, spleen, and lung.
Increased ALT/SGPT levels generally indicate liver disease linked to hepatic necrosis, including cirrhosis, viral/trophic hepatitis, and obstructive jaundice.
In acute viral or toxic hepatitis, ALT/SGPT levels typically exceed AST/SGOT levels; however, in chronic liver disease, ALT/SGPT levels are often lower than AST/SGOT levels.
Elevated ALT can occur due to severe trauma, circulatory failure, hypoxia, myocardial infarction, and hemolytic disease.

Description

Test your knowledge on liver function and the role of serum proteins, including albumin and prothrombin time. Understand how liver damage affects these parameters, as well as the significance of SGOT/AST levels in various organs. This quiz is essential for students studying human physiology and liver health.