Muscle & Liver

Question 1

Muscle origin enzymes

Answer 1

CK
AST
LDH

Question 2

Creatine kinase (CK)

Answer 2

Leakage
Skeletal/Cardiac/smooth muscle
Short half life

Question 3

Aspartate aminotransferase (AST)

Answer 3

Leakage

Skeletal muscle, hepatocytes, RBCs

Question 4

Lactate dehydrogenase (LDH)

Answer 4

Leakage
Multiple sources
Not usually used

Question 5

What is myoglobinuria indicative of?

Answer 5

Muscle necrosis

Question 6

What protein is released from damaged cardiac and skeletal muslce that can be measured by immunoassay?

Answer 6

Troponin (cTnI)

Question 7

Natriuretic Peptides

Answer 7

Released in response to cardiac myocyte stretch to cause vasodilation

Pro-BNP

Question 8

Aspartate aminotransferase (AST)

Answer 8

Leakage

Skeletal muslce, hepatocytes, RBCs

Question 9

Alanine aminotransferase (ALT)

Answer 9

Leakage

Hepatocytes

Question 10

Sorbitol dehydrogenase (SDH)

Answer 10

Leakage

Hepatocytes

Question 11

Glutamate dehydrogenase (GLDH)

Answer 11

Leakage

Hepatocytes

Question 12

Cholestasis

Answer 12

Impaired biliary flow
Intrahepatic or extahepatic
Markers: Tbili, Chol, Bile acids, ALP, GGT

Question 13

What two enzymes increase due to cholestasis?

Answer 13

ALP

GGT

Question 14

Alkaline phosphatase (ALP)

Answer 14

Induction
Hepatocytes, osteoblasts, colostrum
*Important if see any increase in cats

Question 15

When can you see an increase in ALP?

Answer 15

Cholestasis
Glucocorticoid induction
Non-steriodal drug induction
Young animals (osteoblastic)
Pathologic osteoblastic (osteosarcoma)
Colostrum

Question 16

Gamma glutamyltransferase (GGT)

Answer 16

Induction

Biliary epithelium, renal tubules (seen in urine), colostrum

Question 17

What do leakage enzymes tell you about liver diease?

Answer 17

Hepatocellular injury

ALT, AST, SDH

Question 18

What do induction enzymes tell you about liver disease?

Answer 18

Cholestasis

ALP, GGT

Question 19

Excretory liver function tests

Answer 19

Bilirubin
Bile acids
Ammonia

Question 20

Synthetic liver function tests

Answer 20

Albumin
Urea (BUN)
Cholesterol
Glucose
Coagulation factors

Question 21

Pre-hepatic hyperbilirubinemia

Answer 21

> 50% unconjugated

Question 22

Hepatic/post-hepatic hyperbilirubinemia

Answer 22

> 50% conjugated

Question 23

What are you testing when you look at bile acids?

Answer 23

Hepatocellular disease (healthy hepatocytes)
Cholestasis (intestinal absorption)
Hepatic circulation (portal circulation)

Question 24

What could cause an increase in bile acids?

Answer 24

Decreased hepatic clearance (shunt, dysfunction)

Decreased hepatic biliary excretion (cholestasis)

Question 25

Ammonia

Answer 25

Accumulates during liver dysfunction
Hepatic encephalopathy
Complicated to test accurately

Question 26

Causes of hyperammonemia

Answer 26

Decreased blood clearance (shunt, dysfunction)

Increased production or intake (physiologic, toxicosis, intestinal disease)