What are eicosanoids?
biologically active 20c fatty acids
What prostanoids are made from them?
What do these substances do?
act locally as paracrines via g-protein linked cellular receptors
What are the three series of eicosanoids?
2: alpha linolenic
Which one of the three is conditionally essential?
meat eaters get plenty in diet
can be synthesized from DHGLA in series I if enzyme pathway intact
Each series gives rise to its own set of prostaglandins, leukotrienes and thromboxanes.
Code for those are PG1, LK2, TX3, etc.
Series 2 mostly inflammatory, series 1 & 3 mostly antiinflammatory.
found in vegetables, seeds, nuts
converted by delta-6 desaturase-->gamma-linolenic (GLA)-->DHGLA-->series 1 cytokines
delta-6 desaturase inhibited by trans fats, stimulated by insulin
GLA found in EPO, borage, black currant???
enzyme for DHGLA-->PG1, TX1 and LK1 is cox or lipox
DHGLA can convert to series 2 which is why arachidonic conditionally essential
sources: animal fats
delta-5 desaturase stim by insulin, blocked by EPA, DHA, glucagon
What is PLA-2?
removes lipids from phospholipid bilayer that is the cell membrane
What stimulates phospholipase A2?
angiotensin 2, bradykinin, epi, thrombin
What inhibits phospholipase A2?
What does lipoxygenase make from arachidonate?
What does cyclo-oxygenase make from arachidonate?
PGs and TXs
What inhibits cyclo-oxygenase?
sources: seed oils: walnuts, flaxseed, perilla, chia, hemp, also green leaves
delta-6 desaturase blocked by stress hormones, age, cancer, stim by B6, Mg, Zn
inhibited by trans fats
alpha linolenic-->EPA-->DHA-->PG, TX, LK 3
EPA in salmon, herring, mackerel