Diagnostic, Therapeutic and Analytical Uses of Enzymes and MCQs

Diagnostic uses of enzymes

Enzymes are known as marker of cellular damage. The amount of enzymes present in the plasma is used for the investigation of the diseases of liver, heart, skeletal muscle, biliary tract etc.

Classification of diagnostically important enzymes:

• Liver, cardiac and skeletal enzymes
• Biliary tract enzymes
• Digestive enzymes of pancreatic origin

Liver, cardiac and skeletal enzymes:- Enzymes in this category include:

1. Aminotransferases or transaminase

• Increases plasma Aspartate aminotransferase(AST) level and increased plasma alanine aminotransferase (ALT) level indicates liver diseases.
• Increased AST level occurs after myocardial infraction as heart muscle contains relatively high concentration of AST.
• AST activity levels are increased in muscular dystrophy and dermatomyositis.
• Moderate increase of both AST and ALT have been observed after the intake of alcohol, or after taking various drugs such as salicylates ampicillin etc.

2. Alkaline phosphatase:- Plasma ALP level are particularly used in the investigation of bone diseases and hepatobiliary diseases.

Biliary tract enzymes:-  Enzymes included in this category are

1. 5’-Nucleotidase (nucleotide phosphate NTP)- Increased level of serum NTP occur in hepatobiliary diseases in which there is obstruction in the secretion of bile.
2. Gamma-glutamyl transferase GGT- Increased level of GGT occurs in all form of liver diseases. It is used for the investigation of obstructive jaundice, cholangitis (inflammation of bile duct) and cholecystitis (inflammation of gall bladder).

Digestive enzymes of pancreatic origin:- The digestive enzymes are investigated for the diagnosis of pancreatic diseases

1. Alpha-amylase:- Assays of amylase in the serum and urine are primarily used for the diagnosis of pancreatic diseases like pancreatitis, cholecystitis, tumors etc.
2. Trypsin:- Determination of serum trypsin can be used to screen for the cystic fibrosis during first 6 weeks of life. Also it is used in pancreatic ductules.
3. Chymotrypsin:- As with amylase and trypsin, elevation of serum chymotrypsin level if reaches 8 times the normal level than it indicates renal failure.

Enzymes as tumor marker

Elevated enzyme level may mark the presence of malignancy. The below table describes the same:

Analytical uses of enzymes

Enzymes can be used as reagents and labels.

Enzymes as reagents:- Enzymes are widely used in the laboratories as reagents for the estimation of serum constituents.

Enzymes as labels:- Many enzymes are used as the label in various immunoassays for the determination of serum level of drugs, hormones, and other compounds. Examples include:

• Glucose-6-phosphate dehydrogenase
• Alkaline phosphatase
• Beta-galactosidase
• Peroxidase

Therapeutic uses of enzymes

Some enzymes are used in the treatment of several diseases of human being, Like:

• Bacterial asparginase is used for the treatment of some type of leukemia.
• Chymotrypsin is used in ophthalmology for dissolving ligaments of the lens during the extraction.
• Collagenase is use to clean the wound by removing the dead tissue of dermal ulcers and severe burns.
• Hyaluronidase is used to promote the absorption of the drugs injected subcutaneously.
• Penicillinase: Used for the treatment of persons suffering from penicillin allergy.
• Streptokinase and urokinase: Used in myocardial infraction to dissolve the clot or purulent material.
• Pepsin, lipase, amylase elastase, trypsin peptidase are used in GIT disorders and chronic pancreatitis.

Some other enzymes and its therapeutic is described in below given image.

Multiple Choice Questions (MCQs)

1. In how many types, uses of enzymes are classified?
A. 2

B. 3

C. 4

D. 5

2. What indicates liver diseases?
A. Increased AST

B. Increased ALT

C. Decreased AST

D. Both A and B

3. Assay of which is used for the diagnosis of pancreatitis?
A. Bacterial asparginase

B. Amylase

C. Trypsin

D. Chymotrypsin

4. Elevated level of aldolase indicates which type of cancer?
A. Liver

B. Lung

C. Bone

D. Prostate

5. Which of the following is use for the treatment of leukemia?
A. Bacterial asparginase

B. Amylase

C. Trypsin

D. Chymotrypsin

6. Match the following enzyme indicating disease-
a. Chymotrypsin 1. Liver cancer
b. Trypsin 2. tumors
c. Amylase 3. Cystic fibrosis
d. 5-nucleotidase 4. Renal failure

7. Which of the following enzyme is used as a label for the determination of serum level of drugs?
A. Peroxidase

B. Alkaline phosphatase

C. Glucose-6- phosphate dehydrogenase

D. All of the above

8. Which of the following statement is NOT true?
A. AST was formerly known as glutamate oxaloacetate transaminase
B. Penicillinase is used for treatment of penicillin allergy
C. Pepsin is used for the treatment of jaundice
D. Urokinase is used in myocardial infraction

9. Elevated level of which enzyme indicates renal failure?
A. Bacterial asparginase

B. Amylase

C. Trypsin

D. Chymotrypsin

10. What occurs during hepatobiliary diseases?
A. Increased level of NTP

B. Increased level of GGT

C. Decreased level of NTP

D. Decreased level of GGT

11. Increased level of GGT indicates which disease?
A. Obstructive jaundice

B. Pancreatitis

C. Renal failure

D. All of the above

12. Moderate increase in level of AST and ALT occur after the intake of which liquid?
A. Tea

B. Alcohol

C. Orange juice

D. None of the above

13. What happens to the level of AST after myocardial infraction?
A. Increased

B. Decreased

C. Constant

D. None of the above

14. Bone cancer is indicated by the elevated level of which enzyme?
A. Aldolase

B. Alkaline phosphatase

C. Kinase

D. None of the above

15. Enzymes are known as marker of —— damage?
A. Tissue

B. Organ

C. Both

D. None of the above

ANSWERS:-

1. 3
2. Both A and b
3. Amylase
4. Liver
5. Bacterial asparginase
6. a – 4 b – 3 c – 2 d – 1
7. All of the above
8. Pepsin is used for the treatment of jaundice
9. Chymotrypsin
10. Increased level of NTP
11. Obstructive jaundice
12. Alcohol
13. Increased
14. Alkaline phosphatase
15. None of the above