Cholesterol By SUHA AL THUBAITI Supervisor by: Dr. Wadiah Backer

1
CholesterolBy SUHA AL THUBAITI Supervisor
byDr. Wadiah Backer
2
Cholesterol sources

• Animal food
• Synthesized in animal liver

3
Cholesterol function

• Maintenance of cell membrane structure and
  function
• Synthesis of Bile acids
• Production of various steroid hormones
• Synthesis of Vit.D

4
Cholesterol synthesis in the liver

• Cholesterol is a member of steroid family, Acetyl
  CoA is the starting point for cholesterol
  synthesis

5
(No Transcript)
6
Cholesterol regulation by 2 mechanisms

• Feed back inhibition by Cholesterol to HMG-CoA
  reductase enzyme
• HMG-CoA reductase enzyme inhibited by
  phosphorylation by cyclic AMP kinase

7
(No Transcript)
8
Cholesterol transport involve different
lipoproteins

• Chylomicrons pick up dietary cholesterol and fat
  from the intestine to adipose tissue
• VLDL transport fats to tissues
• LDL transport excess cholesterol to tissues
• HDL carries cholesterol from cells back to the
  liver.

9
Lipoproteins

• Chylomicron HDL

• LDL

10
The Basic Components of Cholesterol Synthesis and
Excretion.
11
Receptor mediated endocytosis

• LDL inter cells by LDL receptors forming
  endocytic vesicles and cholesterol utilized by
  the cells to make membranes and synthesis other
  steroids.

12
Cholesterol association to heart disease

• There are 2 main routs by which cholesterol level
  can rise to dangerous level
• Genetic predisposition
• Life style/ Diet

13
How LDL cause heart attacks?

• As LDL cholesterol rise in the blood plaques
  begin to form on arterial walls blocking blood
  flow.

14
What to do to reduce cholesterol level?

• Eat low diet cholesterol
• Drugs such as Lipitor and mevinolin by inhibiting
  HMG CoA reductase activity
• Exercise, burns fats and increase HDL level
• Quit Smoking