Liver - Ex 3

Question 1

Leakage enzyme

Answer 1

enzymes leaking from injured cells

Question 2

Induced enzyme

Answer 2

cells producing abnormally high numbers of enzymes

Question 3

Name main leakage enzymes

Answer 3

ALT
AST
SDH

Question 4

Tissues of origin ALT and AST

Answer 4

ALT - cytoplasm

AST - cytoplasm & mitochondria

Question 5

From what other tissue may ALT originate?

Answer 5

Muscle

Question 6

Name two inducible enzymes

Answer 6

ALP

GGT

Question 7

When ALP is increased, what are the 3 possible causes (major)?

Answer 7

1. hepatobiliary dz
2. osteoblastic dz
3. induction by drugs

Question 8

Two aspects of Alp that are different in the cat?

Answer 8

Short 1/2 life

Lower liver ALP concentration per gram of tissue

Question 9

Causes of increased GGT

Answer 9

1. Cholestasis
2. Biliary hyperplasia
3. Drug induction (dogs)

Question 10

Where does bilirubin come from?

Answer 10

Degradation of Hgb

Question 11

Bilrubin metabolism & hepatocytes

Answer 11

u-bilirubin is conjugated (more water soluble) –> moves to bile caniculi

Question 12

Biliary system and bilirubin metabolism

Answer 12

conjugated bilirubin passes with bile into small intestine –> converted to urobilinogen & excreted in feces

Question 13

Causes of increased bilirubin

Answer 13

1. Hemolysis –> inc production of bilirubin
2. Hepatic dz –> dec uptake or conjugation
3. Cholestasis –> dec bilirubin excretion

Question 14

What effect does starvation or going off feed have on bilirubin in the horse?

Answer 14

Hyperbilrubinemia (5-7)

higher levels indicate other problem

Question 15

How and where are bile acids produced

Answer 15

Bile acids are synthesized in hepatocytes from cholesterol

After synthesis, bile acids are stored and concentration in the gallbladder

Bile acids emulsify fat

Question 16

Role of the intestine in bile acid metabolism

Answer 16

primary bile acids converted to secondary bile acids –> most bile acids absorbed by ileum into portal circulation –> cleared in 1st pass of the liver

Question 17

Causes of increased bile acids

Answer 17

1. Blood is shunted (abnormal portalcirculation) –> impairs first pass clearing
2. Decreased functional hepatic mass –> dec uptake of bile acids from portal circulation
3. Cholestasis –> obstruction

Question 18

What is the major indication for performing bile acid assay>?

Answer 18

Increased liver enzymes, but normal total bilirubin

Question 19

5 substances whose concentration in serum may decrease with hepatic failure?

Answer 19

1. Albumin
2. Globulins
   - can inc
3. Glucose
   - can inc

4, Cholesterol
- can inc

5. Urea