Lecture 26 - Liver 1 Flashcards
What process is needed to cause an increase in serum blood enzymes of SURFACE enzymes?
INDUCTION - induced by triggers e.g. neoplasm or drugs
Is there any diagnostic importance of decreased serum enzymes activity?
No
For CYTOPLASMIC enzymes how is the degree of severity determined?
number of times increase (i.e. 2x = minor, 50x = quite severe damage)
What organ is alanine transaminase (ALT) mainly specific for and what other cell type can it come from?
specific for hepatic injury. Can come from myocytes
Is the ALT in myocytes greater for cats or for dogs?
ALT is minimal in cats, but is present in dogs
Provide an example of an event that could cause and increase in serum ALT activity with concurrent increase in serum CK activity:
If the animal was hit by a car
Comment on the usefulness of ALT in determining between damage to the muscle and liver in swine, horses and cattle
Not very useful. Muscle ALT = liver ALT
When does ALT normally peak in dogs?
generally peaks at 1-2 days
Comment on the sensitivity and specificity of AST:
Activity high muscle = cardiac = hepatocyte (poor sensitivity)
Present in reversible and irreversible cell injury (high sensitivity)
What would be your interpretation of increased serum AST and concurrent SDH activity?
Acute or active hepatocellular injury
Where is sorbitol dehydrogenase (SDH) typically found?
Highest concentration is in the liver followed by kidney - SDH is considered liver specific in all species
Comment on the specificity and sensitivity of SDH within large animals, what test could be used if we wanted higher sensitivity?
Specificity = basically 100%
Sensitivity = about 50%
GLDH is considered to be more sensitive
Why is GLDH only release with irreversible cell damage?
Because it is located in the mitochondria
What is the specificity of GLDH?
Almost 100%
What organ contributes all of the serum GGT and what particular cell type is it associated with?
Mainly associated with the liver and is released from biliary epithelial cells
What are three pathological conditions that lead to GGT?
- Cholestasis
- Biliary hyperplasia - usually toxin related
- Drugs or hormones - e.g. corticosteroids
Where is L-ALP released from?
Hepatocytes and biliary epithelium
Where is B-ALP released from?
Osteoblasts
Where is C-ALP released from?
Hepatocytes when stimulated by corticosteroids
Where is I-ALP released from?
released from intestine
What is the half life of C-ALP and L-ALP?
3 days - but only a few hours in cats
What does alkaline phosphatase (ALP) have a high sensitivity for detecting?
High diagnostic sensitivity for detecting cholestasis
Provide a physiological and a pathological condition where B-ALP would be increased:
Young animals due to bone modelling
Osteosarcoma = prognostic indicator
