(8) III. TESTS FOR DETOXIFICATION FUNCTION

Question 1

• Used to assess the extent of liver damage.
• Indicator of cell injury in early or localized liver disease (hepatocellular/functional disease)

Answer 1

Enzyme tests

Question 2

Significant Hepatic enzymes:

Answer 2

1. AST
2. ALT
3. GGT
4. LDH
5. 5’N
6. OCT (Ornithine Carbamoyl Transferase)

Question 3

• Diagnostic marker of hepatic failure
• Detoxified into urea (liver), then eliminated by the kidneys (urine)

Answer 3

Ammonia

Question 4

• Diagnostic marker of hepatic failure
• Detoxified into urea (liver), then eliminated by the kidneys (urine)

Answer 4

Ammonia

Question 5

Preferred spx for ammonia

Answer 5

venous blood

Question 6

Preferred spx for ammonia

Answer 6

o venous blood
o Plasma using Heparin, EDTA, Potassium oxalate
o Kept in ice water during transport
✓ If not placed in ice → false ↓ in NH3
✓ Bcos some bacteria can convert NH3 to Urea

Question 7

During collection of NH3:

Answer 7

o During collection, tourniquet <1min use. only
o Fist clenching : false ↑

Question 8

Spx precautions for NH3:

Answer 8

o Smoking: false ↑NH3 by 100-200ug/L per cigar
✓ Both for px & phlebotomist bcos NH3 sticks to clothing.
o Exercise
o Probing of vein
o Under filling of tube
o Hemolysis: RBC NH3 are 2-3x more concentrated than plasma NH3
✓ False ↑ in NH3

Question 9

NH3 Storage:

Answer 9

Ice or Frozen

Question 10

produced by deamination of AA

Answer 10

Ammonia

Question 11

How is NH3 formed?

Answer 11

Proteins are long chains of AA connected together by peptide bonds. When these bonds are destroyed, AA are liberated which are then transaminated & deaminated forming Ammonia.

Question 12

In hepatic failure, what happens if ammonia is not converted to urea?

Answer 12

accumulation of ammonia forms glutamate which is neurotoxic.

Question 13

NOTE!

Answer 13

Ammonia must be converted to urea thru the urea cycle / Krebs henseleit cycle in the LIVER & which is then excreted in urine.

Question 14

↑glutamate

Answer 14

= coma