II. Definitions
- Arachidonic Acid
- Arachidonic Acid is a polyunsaturated Essential Fatty Acid present in human fat, liver, brain and glandular organs
- Derived from dietary Linoleic Acid
- Precursor of Prostaglandins, prostacyclins, Thromboxanes, and Leukotrienes.
III. Physiology: Arachidonic Acid Derivatives (Eicosanoids)
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General
- Derived from Arachidonic Acid via cyclooxygenase pathway
- Basic structure is a 5 carbon ring "head" with two 6 to 9 carbon chain "legs"
- Functions vary by specific molecule, but function in general is summarized here
- Thromboxanes
- Increase Platelet aggregation
- Leukotrienes
- Leukocyte chemotaxis
- Prostacyclin
- Inhibits Platelet aggregation
- Vasodilates
- Prostaglandins
- Some Prostaglandins contract Smooth Muscle (e.g. Vasoconstriction, bronchoconstriction, uterine contraction)
- Some Prostaglandins increase inflammatory response as well as pain and fever