VPT 321: Veterinary Neuropharmacology (2+1) copy 1

LIPID DERIVED AUTACOIDS

The 3 main groups of arachidonic acid metabolites are:

• Prostaglandins (PG)
• Leukotrienes (LT)
• Platelet activating factor (PAF)

Arachidonic acid is one of 3 essential fatty acids.

• An essential fatty acid is one that cannot be formed de novo. It must be obtained from the diet.
• The essential fatty acids required are:
  • Eicosatrienoic acid - 3
  • Eicosatetraenoic acid - 4
  • Eicosapentaenoic acid - 5
• Arachidonic acid is not a circulating compound, nor does it have any intrinsic biological activity.
• Arachidonic acid is incorporated into phospholipids, which make up the membranes of all cells. Hence, arachidonic acid is present in all cells of the body.
• The first step in the metabolism of arachidonic acid is the removal of it from the phospholipid.
• This step is done by phospholipase A₂ or C.