GGT Determination

Question 1

Where was GGT first identified?

Answer 1

Kidney tissue

Question 2

Has the highest level of GGT

Answer 2

Renal tissue

Question 3

Where does serum GGT originate?

Answer 3

Hepatobiliary system

Question 4

TRUE or FALSE: GGT is elevated in liver diseases.

Answer 4

True

Question 5

GGT levels may increase __-__ times the normal levels in intra- or post-hepatic biliary obstruction.

Answer 5

5-30

Question 6

GGT is elevated - times than normal in infectious hepatitis.

Answer 6

2-5

Question 7

GGT catalyzes the transfer of the gamma-glutamyl group from (substrate) ________________ to (acceptor) ______________ at a pH of 8.2. The product of the reaction is a yellow compound known as ________.

Answer 7

Substrate: 
L-gamma-glutamyl-p-nitroanilide
Acceptor:
Glycylglycine
Product:
p-nitroaniline

Question 8

The rate of increase in absorbance is directly __________ to GGT activity at ___ nm.

Answer 8

proportional

405 nm

Question 9

Methods for GGt activity determination

Answer 9

1. Szasz-Rosalki IFFC Recommended Method
2. Persijn and Van der Silk Method
3. Goldberg Method

Question 10

This is the reference method for GGT activity determination

Answer 10

Szasz-Rosalki IFFC Recommended Method

Question 11

In 1963, they introduced gamma-glutamyl-p-nitroanilide as a substrate.

Answer 11

Orlowski and Meister

Question 12

They added glycylglycine as an acceptor in 1966, resulting in an increase in reaction rate.

Answer 12

Kulhanek and Dimov

Question 13

L-gamma-glutamyl-3-carboxyl-4-nitroanilide + glyclyglycine = 5-amino-2-nitrobenzoate

Answer 13

Szasz-Rosalki IFFC Recommended Method

Question 14

TRUE or FALSE: Szasz and Persijn substituted L-gamma-glutamyl-p-nitroanilide with GLUPAC, which is a more stable reagent.

Answer 14

True

Question 15

_____________ has a better absorbance at 410 nm.

Answer 15

5-amino-2-nitrobenzoate

Question 16

This assay is based on the hydrolysis of L-gamma-glutamyl-3-carboxyl-4-nitranilide.

Answer 16

Persijn and Van der Silk Method

Question 17

TRUE or FALSE: L-gamma-glutamyl-3-carboxyl-4-nitranilide can directly produce its own chromogen.

Answer 17

True

Question 18

This method uses L-gamma-glutamyl-beta naphthylamide as a substrate

Answer 18

Goldberg Method

Question 19

The preferred specimen for GGT determination.

Answer 19

Non-hemolyzed serum

Question 20

Aside from non-hemolyzed serum, this specimen type can also be used.

Answer 20

EDTA plasma

Question 21

It may produce turbidity in the reaction.

Answer 21

Heparin

Question 22

Decrease GGT activity by 1-15%

Answer 22

Citrate
Oxalate
Fluoride

Question 23

Decreases GGT activity by 5-7%

Answer 23

Hemoglobin (100-500 mg/dl)

Question 24

Serum GGT is stable for at least __ hrs. at room temp.

Answer 24

8

Question 25

Serum GGT is stable for 1 month at ___

Answer 25

4 degrees Celsius

Question 26

Serum GGT is stable for a year at _____

Answer 26

-20 degrees Celsius

Question 27

Falsely elevate GGT levels

Answer 27

Barbiturate, phenytoin, and other anticonvulsant drugs

Question 28

Exhibit negligible interference (<5%)

Answer 28

Bilirubin

Question 29

What is the linearity of GGT determination methods?

Answer 29

up to 600 IU/L

Question 30

If samples exceed the linearity limit, what should be done?

Answer 30

Samples should be diluted with an equal amount of saline and re-assayed.

Question 31

Final results of diluted samples should be multiplied by __

Answer 31

2

Question 32

The normal value for adult males

Answer 32

up to 45 IU/L

Question 33

The normal value for adult females

Answer 33

up to 30 IU/L