Download MBBS Biochemistry PPT 11 Clinical Importance Of Enzymes Lecture Notes

Download MBBS (Bachelor of Medicine, Bachelor of Surgery) 1st year (First Year) Biochemistry ppt lectures Topic 11 Clinical Importance Of Enzymes Notes. - biochemistry notes pdf, biochemistry mbbs 1st year notes pdf, biochemistry mbbs notes pdf, biochemistry lecture notes, paramedical biochemistry notes, medical biochemistry pdf, biochemistry lecture notes 2022 ppt, biochemistry pdf.


Clinical Impor tance

of Enzymes

Clinical Importance of Enzymes

Disorders

Diagnosis of Diseases

Pharmacologic agents and Gene Therapy
Enzymatic Diseases

? Thousand of diseases occurs due to enzymatic defects
? Most of them are rare and inherited

- May affect Metabolic pathways: carbohydrate, lipid, proteins
- May affect Physiological processes like digestion
- May affect circulating enzyymes like antiproteases

Phenyl ketonuria

Phenylalanine

Phenylalanine Hydroxylase

Tyrosine

1 in 10000 live births
Mental Retardation
Albinism
Lactase Deficiency

? A very common disorder
? Milk indigestion
? Characterized by bloating, abdominal cramps and diarrhoea

Emphysema

? Due to 1 antitrypsin deficiency
? Inhibitor of serine protease- Elastase
? Neutrophilic elastase inhibits bacterial growth
? Elastase may damage lung tissue elastin if escapes
? Kept in check by antiprotease 1 antitrypsin
Diagnostic utility

Detection of Enzymes for diagnosis or

prognosis of disease

Enzymes as analytical agent

Detection of Enzymes for diagnosis of

disease

Disorders

Enzymes

Liver Function Tests

SGOT, SGPT, ALP, GGT

Cardiac Function Tests

CK-MB, Troponins

Pancreatic Enzymes

Amylase, Lipase

Muscle Enzymes

CK, LDH

Bone Enzymes

ALP , ACP
Plasma Functional Enzyme vs Plasma

Nonfunctional enzymes

Plasma functional Enzyme Plasma non-functional Enzymes

? Present in blood at all times

? Present in blood in minimal amounts

? Perform physiological functions in

? No known physiological function in blood

blood

? Eg. SGOT, SGPT, Amylase, CK-MB

? Eg. Lipoprotein lipase,

? Increased in diseased conditions due to

Pseudocholinesterase, Clotting factors

tissue damage, altered enzyme production

? Decrease in diseased conditions like

Liver disease

Isoenzymes

? Multiple forms of enzymes that catalyze the same reaction but differ in their

structure

? Encoded by different structural gene loci
? Differ in physical properties like electrophoretic motility or resistance to heat

inactivation

? Antigenically distinct
? Differ in catalytic properties like Km, Vmax.

? Shows Tissue specific distribution.
Examples of Isoenzymes

Enzyme

Isoenzymes

CK

CK-1 (CK-MM), CK-2 (CK-MB), CK-3 (CK-BB)

LDH

LDH 1-5

ALP

Hepatobiliary, Bone, Intestinal, Placental

Hexokinase

Hexokinase I-IV

Methods for Iso-enzyme detection

? Electrophoresis
? ELISA/Ag-Ab reactions
? Sequencing
? Susceptibility to Inhibitors/ Inactivation
Clinical Scenario 1

Jaundice

? A 69 years old male presented with abdominal pain. His LFTs showed

following results. His sclera was yellow and stools were pale with dark

colored urine.

Tests

Result

Reference Range

Bilirubin

6.0mg/dl

0.3-1.2mg/dl

AST

34 U/L

<50 U/L

ALT

35 U/L

<50 U/L

ALP

870 U/L

30 ? 120 U/L
Clinical Scenario 2

Jaundice

? A 35 years old male presented with malaise, weight loss, generalized

weakness. He noticed dark colored urine for past 2 days. LFTs were as

follows

Tests

Results

Reference Range

Bilirubin

2.5 mg/dL

0.3-1.2mg/dl

AST

900 U/L

<50 U/L

ALT

1200 U/L

<50 U/L

ALP

370 U/L

30 ? 120 U/L

Clinical scenario 3

MI

? A 50 year male presented to ED with tight chest pain radiating to left arm.

Cardiac function tests were as follows

Tests

Results

Reference Range

CK-Total

235 U/L

< 145 U/L

CK-MB

50 U/L

< 24 U/L

Troponin T

15 ng/L

< 10 ng/L
Enzymes as analytical reagents

? Measurement of Metabolites: Uricase, Urease, Glucose oxidase
? Immunoassays: ALP, Horse radish peroxidase, glucose 6 phosphate

dehydrogenase

? Recombinant DNA Technolog y: Restriction Endonuclease, DNA ligase,

DNA polymerase

Therapeutics

? Various drugs are used to inhibit enzymes therapeutically

Disorder

Enzyme

Drug

Cancer

Thymidylate Synthetase

5 fluorouracil

Inflammation

Cyclooxygenase

Aspirin

Gout

Xanthine oxidase

Allopurinol
Therapeutics

? Enzymes are also used as drugs

Disorder

Enzyme as Drug

MI

Streptokinase, tPA ( Thrombolysis)

Gaucher's disease

Glucocerebrosidase (ERT/Gene Therapy)

Cystic Fibrosis

Trypsin

Summar y

Disorders: Metabolic Pathways, Digestion, Circulating

Enzymes

Diagnosis of Diseases: Biomarkers, Analytical agents,

Recombinant DNA technology

Pharmacologic agents and Gene Therapy

This post was last modified on 05 April 2022