eicosanoids Flashcards
Members of eicosanoid family
protanoids, leukotrines, endocanabanoids
Fatty acid precursor determines
the eicosanoid produced
3 Protanoids
Prostaglandins, thromboxanes, prostacyclins
Prostaglandin structure
20 carbons, carboxyl group at C1, C8-C12 form 5-membered ring, hydroxyl/keto groups at 9&11, hydroxyl at 15, trans double bond at 13&14
Thromboxane structure
6 membered carbon ring containing an O atom, substituents attached to 9&10 carbon atom, for thromboxane A2:an O atom connects C9 & C11
Phospholipase C
RL enzyme for eicosanoid synthesis in platelets
Phospholipase A2
rate limiting enzyme for prostaglandins; frees up FA precursor from membrane, produces arachidonic acid
major eicosanoid precursor
arachidonic acid
using the enzyme lipoxygenase, archidonic acid is converted to
leukotrines
using the enzyme Cox (1&2), arachidonic acid is converted to
prostaglandines
cox 1 produces
thrombaxane A2
cox 2 produces
prostacyclin
where is thromboxane located?
platelets
What is the function of thromboxane?
promotes platelet aggregation & vasoconstriction upon vascular injury
-induces thrombosis
where is prostacyclin located?
vascular endothelial cells
what is the function of prostacyclin?
stimulates vasodilation & impedes thrombosis
Thromboxane and prostacyclin _______ & control
oppose one another & control thrombosis
action of aspirin
covalently acetylates COX1&2
effect of aspirin on COX1
COX1 becomes inactivated (antithrombotic)
what is the effect of aspirin on COX 2?
turns off cox2’s ability to produce prostaglandins
-has an anti-inflammatory, pro-resolution effect
do levels of TXA2 or PG12 recover more quickly and why?
PG12 because endothelial cells are nucleated
Arachidnoic acid is a precursor for _____ which is a precursor for _____.
anandamide; endocannabinoids
glutamate is
a neurotransmitter involved in addiction and pain control
Anandamide regulates the release of
glutamate
