Specific enzymes

Question 1

ALT

Answer 1

Alanine transaminase
Hepatocyte specific
Used for dogs and cats
Leakage enzyme

Question 2

ALT half life

Answer 2

2-3days

Question 3

AST

Answer 3

Aspartate transaminase
Cytoplasmic and mitochondrial enzyme
Hepatocyte and skeletal muscles injury
Leakage enzyme
Used in Large animals (hepatocytes) and small animals

Question 4

Half life of AST

Answer 4

7-8 days in horses
<1day in dogs

Question 5

LD or LDH

Answer 5

Lactate dehydrogenase
Cytoplasmic enzyme
Hepatocytes and skeletal muscle
Poor tissue specificity but can mark hepatocyte damage

Question 6

LD half life

Answer 6

< 6hrs in dogs

Question 7

SDH

Answer 7

Sorbitol dehydrogenase
Cytoplasmic enzyme
Hepatocytes
Leakage animals
Used mostly in cattle and horses

Question 8

SDH half life

Answer 8

4hr in dog

Question 9

What enzyme is most hepatocyte specific in LA

Answer 9

SDH

Question 10

What enzyme is most hepatocyte specific in dogs and cats

Answer 10

ALT

Question 11

GMD

Answer 11

Glutamate dehydrogenase
Mitochondrial enzyme
Only released with irreversible cell injury
Hepatocyte specific

Question 12

Half life of GMD

Answer 12

14hr in cattle

Question 13

ALP

Answer 13

Alkaline phosphate
Attached to membrane
Increased production enzyme

Question 14

Half life of ALP

Answer 14

3d in dogs
<8hrs in cats

Question 15

L-ALP

Answer 15

Made by hepatocytes and biliary epithelium

Question 16

C-ALP

Answer 16

Hepatocytes induced by corticosteroids in dogs

Question 17

Increased ALP

Answer 17

-Growing animals have increased bone ALP
-Cholestasis (L-ALP)
-Induction by drugs or hormones (Corticosteroids-> C-ALP, Anticonvulsants-> L-ALP)
-Increased osteoblastic activity (B-ALP)

Question 18

Species differences of ALP

Answer 18

Dogs-> high diagnostic sensitivity for detecting cholestasis and longer half life in dogs

Question 19

GGT

Answer 19

Gamma glutamyltransferase
Membrane associated and inducible
Biliary, renal tubular epithelium, mammary glands

Question 20

Species that have increase in colostral GGT

Answer 20

Cows and dogs
Horses do not (foals have increased GGT but not from suckling like cows and dogs)

Question 21

Tissue sources that cause increased GGT

Answer 21

Biliary epithelial cells -> cholestasis causes biliary hyperplasia or increased with drugs and hormones
(Renal cells excrete it into the urine not the serum)

Question 22

Species differences of GGT

Answer 22

-Horses-> used with cholestasis
-Dogs-> GGT and ALP tend to parallel
-Cats-> Generally GGT better than ALP except with cats with hepatic lipidosis

Question 23

GGT in urine

Answer 23

Use GGT: Crt ratio to determine renal tubular damage

Question 24

CK

Answer 24

Creatine Kinase
Cytoplasmic
Leakage enzyme
Skeletal muscle (in the serum)

Question 25

CK half life

Answer 25

2 hrs in horses and dogs

Question 26

Increased CK

Answer 26

-Damage to skeletal muscle
-Increased muscle catabolism (cats)
-Demyelination or necrosis of neural tissue increased CK in CSF not plasma

Question 27

AMS

Answer 27

Cytoplasmic enzyme
Pancreas
Secreted by kidney

Question 28

Increased AMS

Answer 28

-Pancreatic acinar cell damage
-Decreased renal inactivation or excretion (see with decreased GFR and no pancreatic damage)

Question 29

Half life of AMS

Answer 29

5hrs in dogs

Question 30

LPS

Answer 30

Lipase
Cytoplasmic enzyme
Pancreatic

Question 31

Increased LPS

Answer 31

-Pancreatic acinar cell damage (dogs and cats)
-Decreased renal inactivation or excretion

Question 32

Half life of LPS

Answer 32

2hrs