Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
59 Cards in this Set
- Front
- Back
|
What does a measurement of an enzyme indicate?
|
Its activity, not quantity present
|
|
|
What are enzyme tests called?
|
Kinetic assays
|
|
|
Where in the body do enzymes normally not function?
|
Blood stream
|
|
|
5 reasons for increased enzyme levels
|
- Increased release from damaged cells
- Increased synthesis - Increased levels from hyperplastic or neoplastic cells - Decreased enzyme clearance - Increased from ingestion or absorbance (such as passive transfer) |
|
|
Diagnostic value of enzyme levels in blood that are below reference intervals
|
No diagnostic value since it's not associated with a defined pathology
|
|
|
What fold elevation cut off is most clinically relevant?
|
> 3 fold increase
|
|
|
Pre-hepatic factor that affects liver tests
|
Anemia
|
|
|
Hepatic factor that affects liver tests
|
Primary liver disease
|
|
|
Post-hepatic factor that affects liver tests
|
Gall bladder or bile duct issues
|
|
|
What is there a correlation between in terms of concentration of enzymes released from the liver?
|
Amount of hepatic cells damaged
|
|
|
How much of the liver must be damaged for hepatic insufficiency?
|
70 - 80%
|
|
|
5 substances that are reduced in hepatic insufficiency
|
- Glucose
- Albumin - Urea - Coagulation factors - Cholesterol |
|
|
2 species that ALT is indicative of liver damage in
|
- Cats
- Dogs |
|
|
4 hepatocellular enzymes
|
- ALT
- AST - GLD - SDH |
|
|
2 extrahepatocellular enzymes
|
- ALP
- GGT |
|
|
Two liver values used to assess hepatic injury in large animals
|
- AST
- SDH |
|
|
What species has a unique ALP, and what induces it?
|
Canine
- Induced by Corticosteroids |
|
|
What type of ALP do most instruments measure?
|
No specific one, just total ALP in general
|
|
|
6 causes for ALP elevation
|
- Cholestasis
- Phenobarbitol - Young, growing animals - Osteosarcoma - Mammary neoplasms (dogs only) - Corticosteroids |
|
|
How long does it take after administration of corticosteroids in dogs for ALP levels to rise?
|
One week
|
|
|
What does a rise in ALP indicate in cats? (2)
|
- Cholestasis
- Decreased enzyme clearance |
|
|
3 common causes of increased ALP levels in cats
|
- Cholestasis
- Decreased enzyme clearance - Hyperthyroidism |
|
|
What is the most common cause of increased ALP levels in cats?
|
Hepatic lipidosis
|
|
|
What is GGT primarily associated with?
|
The membranes of biliary epithelial cells
|
|
|
What will increase urine GGT but not blood GGT?
|
Renal tubular damage
|
|
|
Two good indicators of cholestasis in dogs and cats
|
- GGT
- ALP |
|
|
5 causes of increased GGT in cats
|
- Cholangiohepatitis
- Cholangitis - Bile duct obstruction - Hepatic lipidosis - Hepatic neoplasia |
|
|
What's best for detecting cholestasis in cattle and horses?
|
GGT
|
|
|
Two things GGT is used to assess in large animals
|
- Hepatic damage
- Cholestasis |
|
|
What transports billirubin to the liver?
|
Albumin
|
|
|
Source of billirubin
|
By-product of hemoglobin break down and conversion from heme
|
|
|
Two methods of conjugated bilirubin elimination
|
- Bile
- Urine |
|
|
At what level of billirubinemia does the plasma become icteric?
|
> 1.5 mg/dl
|
|
|
At what level of billirubinemia do the tissues become icteric?
|
> 2 - 3 mg/dl
|
|
|
What precedes bilirubinemia in dogs and why?
|
Bilirubinuria
- Has bilirubin conjugation ability in kidneys |
|
|
What bilirubin form increases due to severe hemolysis?
|
Unconjugated
- Conjugated can increase too with chronicity |
|
|
Prehepatic cause for hyperbilirubinemia
|
Hemolysis
|
|
|
Hepatic cause for hyperbilirubinemia
|
Intrahepatic cholestasis
|
|
|
Post-hepatic cause for hyperbilirubinemia
|
Extrahepatic cholestasis
|
|
|
What bilirubin form increases due to extrahepatic cholestasis?
|
Conjugated
- Unconjugated can increase with severity of damage |
|
|
What causes a marked elevation in TBIL in horses?
|
Anorexia for more than 24 hours
|
|
|
What is bile acid produced from?
|
Cholesterol
|
|
|
How long should dogs and cats be fasted for a bile acid test?
|
Overnight
|
|
|
What species does not require fasting for a bile acid test, and why?
|
Horses
- Continually secrete bile |
|
|
What disease process provides the highest increase in serum bile acids?
|
Portosystemic shunts
|
|
|
What disease process provides a moderate increase in bile acid levels? (2)
|
- Acute hepatitis
- Hepatic neoplasia |
|
|
Bile acid level trend in a suspected hepatic insufficiency
|
Increased
|
|
|
Albumin level trend in a suspected hepatic insufficiency
|
Decreased
|
|
|
BUN level trend in a suspected hepatic insufficiency
|
Decreased
|
|
|
Ammonia level trend in a suspected hepatic insufficiency
|
Increased
|
|
|
Glucose level trend in a suspected hepatic insufficiency
|
Decreased
|
|
|
What liver value is the most important to test for in hepatic insufficiency?
|
Ammonia
|
|
|
What enzyme is highly specific and sensitive for muscle damage?
|
Creatinine kinase
|
|
|
What should CK always be evaluated in conjunction with?
|
AST
|
|
|
Two types of CK isoenzymes found in skeletal and cardiac muscle
|
CK-2
CK-3 |
|
|
What does an increased ALT greater than AST increase with no CK increase indicate in dogs and cats?
|
Liver injury
|
|
|
What does an increased AST greater than ALT increase with CK increase indicate dogs and cats?
|
Skeletal muscle injury
|
|
|
What does an increased AST with no CK increase indicate in large animals?
|
Liver injury
|
|
|
What does an increased AST with CK increase indicate in large animals?
|
Skeletal muscle injury
- or - Skeletal muscle injury with concurrent liver injury |
