Eicosanoids Flashcards Preview

Biochem > Eicosanoids > Flashcards

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

Which leukotrienes increase vascular permeability

LTB4, LTC4, LTD4, LTE4 (B thru E increase permeability)