Flashcards in Eicosanoids Deck (22)
1
List 5 types of Eicosanoids
Prostaglandins, Prostacyclins, Thromboxanes, Leukotrienes, Lipoxins
2
Where are arachidonic acids derived from and by what action are they derived?
Arachidonic acid is released from membrane phospholipids via phopholipase A2.
3
What is the rate limiting step in prostaglandin synthesis?
Hydrolysis of arachonic acid
4
How do agents of prostaglandin production function?
Stimulate production by stimulating activity of phosphlipase A2
5
What is the first prostaglandin product?
PGH2
6
What are the 2 components of prostaglandin sythesis?
COX (cyclooxygenase) and PG hydroperoxidase (requires GSH)
7
COX-1 Enzyme
Constitutive (always in constant amount). Found in gastric mucosa, platelets, vascular endothelium, and kidney
8
COX-2 Enzyme
Inducible. Mainly in activated macrphages/monocytes stimulated by PAF, IL-1, or bacterial lipopolysaccharides. Also in smooth muscle cells. Epithelial/ondothelial cells, and neurons.
9
What inhibits COX2 induction?
Glucocorticoids
10
What inhibits COX enzymes?
NSAIDS (more type 2 than 1)
11
Aspirin's MOA
inhibits COX1 more than 2. Involves acetylation of the COX enzyme
12
Steroidal anti-inflammatory drug MOA
inhibit phospholipase A2 activity
13
Major prostaglandins of blood vessels
PGI2 and PGF2
14
What is an important inhibitor of platelet aggregation?
PGI2
15
Major prostaglandin produced by platelets
Thromboxane
16
Actions of prostaglandins
mediators of inflammation, induce redness and heat, increase capillary permeability, pyrogens activate sythesis of prostaglandins, stimulate uterine contraction, inhibit gastric acid secretion
17
What are the products of lipoxygenases?
HPETEs
18
What is another name for HETEs?
leukotrienes
19
What is the most important product of human lipoxygenases?
5-HPETE, because they are converted into leukotrienes
20
Important secretory product of leukocytes
Leukotrienes
21
Leukotrienes' role in inflammatory disorders
mediates inflammatory disorders
22