Liver enzymes

Question 1

How do we measure proteins?

Answer 1

Purification
Antibodies
Function

Question 2

What are some enzymes found in the blood?

Answer 2

CAERULOPLASMIN - Ferroxidase

CLOTTING FACTORS - Proteases

Question 3

Which enzymes are on the liver cell surface

Answer 3

ALP

Question 4

Which enzymes are in the mitochondria?

Answer 4

Mitochondrial AST

Lysosomal SOD

Question 5

What marks the destruction of the cell?

Answer 5

Degradation of the cytoskeleton
Swelling
Mallory hyaline

Question 6

What usually happens in cell death?

Answer 6

It usually blisters in the skin - this then pops open and the bubles can be released into the blood as blebs.
They contain broken down mitochondria

Question 7

Can the cell survive blebing/blistering?

Answer 7

Yes - it may just be a marker of cell damage

Can repair by removing toxin or restoring oxygen

Question 8

Questions about enzymes which are detected

Answer 8

Where did they come from (cell)?
How did they get into the blood?
How quickly does the body remove them from the blood?

Question 9

What are the enzymes in the cytoplasm of the liver cell?

Answer 9

ALT, AST, LD

Question 10

What are the nucleus in the cytoplasm of the liver cell?

Answer 10

DNA synthase

Question 11

WHat is seen in liver necrosis

Answer 11

Virus, Toxin, Anoxia
ALT, AST, LD
esp AST with toxins

Question 12

What is seen in biliary disease

Answer 12

Gallstones, cancer

ALP, GGT

Question 13

Inducing drugs and what they induce?

Answer 13

Alcohol and anticonvulsants

GGT ALT

Question 14

ALT

Answer 14

Changes pyruvate to lactate
The anaerobic metabolism of glucose
This occurs in the liver and muscle (mainly in the liver)

Question 15

AST

Answer 15

Malate shuffle

Question 16

What happens in hepatitis?

Answer 16

ALT – Cytosol – Liver&raquo_space;> muscle , kidney

AST – Cytosol & Mitochondrial – Liver, Muscle, Blood cells

Question 17

Source of ALT and AST?

Answer 17

ALT is in the liver

AST is in all mitochondria

Question 18

What happened if the AST>ALT?

Answer 18

Acute, affecting mitochondria

esp. Acute virus, EtOH

Question 19

What is going on if ALT>AST?

Answer 19

Chronic / resolving
esp. hepatitis
Drugs, Chronic virus, Metabolic

Question 20

Some other viral diseases causing hepaiitis?

Answer 20

• EBV (60%)
• CMV (55%)
• Q FEVER (23%)
• RUBELLA (40% (?))

Question 21

ALT markers?

Answer 21

Normal ALT = 50
MILD  ALT=250
MODERATE ALT=1000
SEVERE  ALT=5000 (half the liver is dead)
ALT of 10000 = going to die

Question 22

What are acute Hep B ALT levels?

Answer 22

Can be very high even 2500 units

Question 23

What is a lethal dose of paracetamol?

Answer 23

15g

Question 24

why would ALT be elevated by AST be normal?

Answer 24

Such a chronic disease that there is not really any significant destruction

Question 25

What happens in the end stage of cirrhosis?

Answer 25

There is not enough liver to actually damage and release liver enzymes

Question 26

Where is ALP produced

Answer 26

Bone, Liver, Placenta

Question 27

Where is GGT produced

Answer 27

Liver, Biliary Epithelium, Renal

Question 28

What does GGT do?

Answer 28

Adds glutamyl groups to generate GLUTATHIONE

Question 29

Why is GGT induced by drugs and alcohol?

Answer 29

Tries to produce gluthatione to coutner the toxic effects of these drugs

Question 30

What does ALP do?

Answer 30

Assists in the transfer across the cell membrane

Question 31

What causes increased production of bilirubin?

Answer 31

Heamolysis

Question 32

What causes decreased excretion of bilirubin?

Answer 32

Gilberts, Dubin Johnson, Hepatitis

Question 33

What happens in extra hepatic cholestasis?

Answer 33

Elevated Conjugated Bilirubin

Question 34

What happens in intrahepatic cholestasis?

Answer 34

No Jaundice | No increase in Bilirubin

Question 35

What do high concentrations of bile do in the liver?

Answer 35

High concentrations will degrade the billary membrane

Question 36

How do GGT and ALP get into the blood stream?

Answer 36

Indirectly via the lymphatics

Question 37

What happens when NAD+ is depleted?

Answer 37

Glutathione is switched on in order to accommodate for the reduction in NAD+

Question 38

If GGT is very high what would you expect to see?

Answer 38

ALT would be up - destruction because the cells cannot keep pace with the high levels of toxins

Question 39

Relationship between liver obstruction and hepatocellular death?

Answer 39

HEPATOCELLULAR DEATH – Death of liver cells – Inflammation & swelling –Biliary Obstruction BILIARY OBSTRUCTION – Inability to excrete toxins – Accumulation of toxins in hepatocyte –Hepatocellular death

Question 40

What happens to fructose?

Answer 40

The liver can convert it to glucose but instead it converts it to fat

Question 41

What is the cause of fatty liver?

Answer 41

Sugar consumption = high fructose levels = conversion to fat