Therapeutic and diagnostic applications of enzymes and isoenzymes.

Introduction:

Enzymes are organic catalysts and proteins in nature.
Isoenzymes or isozymes are proteins which have different molecular and physicochemical properties, but have identical catalytic activity.
The measurement of enzyme level in serum is applied in diagnostic applications.
Detection of certain enzymes in the serum indicates that tissue or cellular damage has occurred resulting in the release of intracellular components into the blood.
In today's lecture we are going to see,

Certain types of leukemia are treated with bacterial asparaginase.
During lens extraction, chymotrypsin is used to dissolve the ligaments between the lens and the cornea.
Dermal ulcers and severe burns can be cleaned with collagenase by removing dead tissue.
The subcutaneous injection of drugs is facilitated with hyaluronidase.
Penicillinase - Treats patients who have an allergy to penicillin.
Streptokinase and urokinase - To dissolve a clot caused by myocardial infarctions.
GIT disorders and chronic pancreatitis are treated with pepsin, lipase, amylase elastase, and trypsin peptidase.

Enzymes are known as markers of cellular damage.
The amount of enzymes present in the plasma is useful for the investigation of diseases of the liver, heart, skeletal muscle, biliary tract etc.
Classification of diagnostically important enzymes:

Elevated levels of Aspartate aminotransferase (AST) and plasma alanine aminotransferase (ALT) are found to indicate liver disease.
As AST concentration in heart muscle is relatively high after myocardial infarction, AST level increases.
In muscular dystrophy and dermatomyositis, AST activity levels are elevated.
Alcohol consumption or the consumption of various drugs like salicylates, ampicillin, etc. are associated with moderate increases in AST and ALT.

Elevated ALP levels in the plasma are particularly useful in the diagnosis of bone and liver conditions.

GLD is increased in the serum of patients with hepatocellular damage, offering differential diagnostic potential in the investigation of liver disease.
GLD is released from necrotic cells and is of value in estimation of the severity of liver cell damage.

Amylase measurements in the serum and urine are typically used to diagnose pancreatic diseases like pancreatitis, cholecystitis, or tumors.

During the first six weeks after birth, serum trypsin levels can be measured to screen for cystic fibrosis.
Pancreatic ductulus are also screened with serum trypsin.

A serum chymotrypsin level exceeding eight times the normal value indicates renal failure, as with amylase and trypsin.

In hepatobiliary diseases in which bile secretion is obstructed, 5'-nucleotidase (nucleotide phosphate NTP) levels are found to be elevated.
Gamma-glutamine transferase GGT-

Increased levels of GGT occur when the liver is dysfunctioning with any type of disease.
These tests are used to detect obstructive jaundice, cholecystitis (inflammation of the gallbladder) and cholangitis (inflammation of the bile ducts).