FNN200 - Week 8 Eicosanoids

Eicosanoids

Series 2 & 4 Eicosanoids

Derived from ARA (n-6); includes prostaglandins, thromboxanes, leukotrienes; negative health effects

Series 3 & 5 Eicosanoids

Derived from EPA (n-3); includes prostaglandins, thromboxanes, leukotrienes; positive health effects

DHA-derived Eicosanoids

Derived from DHA (n-3); not part of numbered series; includes lipoxins, resolvins, and neuroprotectin

Prostaglandins

Regulate muscle contraction and heart rate

ARA-derived Prostaglandins

Proarrhythmic

EPA-derived Prostaglandins

Antiarrhythmic

Thromboxanes

Regulate platelet aggregation and vasoconstriction

ARA-derived Thromboxanes

Promote blood clotting and vasoconstriction

EPA-derived Thromboxanes

Suppress blood clotting and promote vasodilation

Leukotrienes

Regulate blood pressure and inflammation

ARA-derived Leukotrienes

Pro-inflammatory

EPA-derived Leukotrienes

Anti-inflammatory

Cyclooxygenase (COX)

Converts ARA into series 2 eicosanoids and EPA into series 3 eicosanoids

Lipoxygenase (LOX)

Converts ARA into series 4 eicosanoids and EPA into series 5 eicosanoids

Eicosanoid Competition

Excess omega-6 decreases EPA; excess omega-3 decreases ARA; LA (n-6) and ALA (n-3) require the same COX and LOX enzymes to convert into derivatives

Linoleic Acid (LA)

Omega-6 fatty acid; precursor for ARA-derived eicosanoids

Alpha-Linolenic Acid (ALA)

Omega-3 fatty acid; precursor for EPA-derived eicosanoids