cholesterol: synthesis, regulation and clinical importance

1. CHOLESTEROL:
synthesis, regulation and
clinical importance
Presented By:
Amar S. Yadav
Group G
Biochemistry Department

2. Cholesterol
 It is the most abundant animal sterol.
 Source:
•Dietary intake
•Endogenous synthesis
 Important for:
•Bile salts
•Steroid hormones
•Cell membrane component
•Lipoprotein

3. Cholesterol Synthesis
 Site
•Liver(mainly)
•All nucleated body cells
 Precursor
• Acetyl- CoA

4. Synthesis:

5. Steps:
•Formation of Aceto Acetyl CoA
•Formation of HMG-CoA

6. ●Formation of Mevalonate
●Formation of Isoprenoid units

7. ●Formation of Squalene and its conversion to Cholesterol

8. Regulation:
 Feedback Control
 Hormonal Regulation
 Inhibition by drugs
 Bile acids and fasting

9. Clinical Importance:
Lipid Profile:

10. Hypercholesterolemia:(›200mg/dl)
1. Diabetes mellitus: Acetyl CoA
2. Hypothyroidism(myxoedema): HDL receptor on hepatocytes
3. Obstructive jaundice: Obstruction in excretion
4. Nephrotic syndrome: Plasma lipoprotein fraction
5. Familial hypercholesterolemia: Defective LDL receptor
or mutation in ligand region of apo B-100
 Hypercholesterolemia is associated with Atherosclerosis and
Coronary heart disease (more specifically LDL-Cholesterol)

11. Hypocholesterolemia : (<150mg/dl)
1. Hyperthyroidism
2. Malnutrition
3. Mal-absorption syndrome
4. Liver disease

12. References:
 Biochemistry ( U. Satanarayana and U. Chakrapani)
 Textbook of Biochemistry for Medical Students
(Damodaran M. Vasudevan and S. Sreekumari)