Arachidonic Acid Derivatives (4 star!!!) Flashcards Preview

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Flashcards in Arachidonic Acid Derivatives (4 star!!!) Deck (20):
1

What cell membrane component is cleaved to form arachidonic acid? Enzyme?

Phosphatidylinositol--> Phospholipase A2 catalyzes

2

What enzyme cleaves arachidonic acid to make leukotrienes? What product is formed?

Lipoxygenase--> Hydroperoxides (precursor to all LTs)

3

What drug inhibits lipoxygenase? Purpose?

Zileuton--> blocks leukotriene synthesis to prevent bronchoconstriction

4

What are the two functions of leukotrienes? Which ones responsible for each?

1. Neutrophil chemotoxis (LTB4)
2. Increased bronchial tone (LTC4, LTD4)

5

What two drugs are leukotriene receptor antagonists?

1. Zafirlukast
2. Montelukast (approved for children)

6

What molecule is the precursor for prostacyclins, prostaglandins, and thromboxane? What enzyme catalyzes its creation from arachidonic acid?

Endoperoxides--> Cyclooxygenase catalyzes (COX-1, COX-2)

7

4 functions of Prostacyclin (PGI2)

1. decreased platelet aggregation (platelet-gathering inh.)
2. decreased vascular tone
3. decreased bronchial tone
4. decreased uterine tone
* DECREASES EVERYTHING

8

4 functions of prostaglandins (PGE2, PGF2 alpha)

1. increased uterine tone
2. decreased vascular tone
3. decreased bronchial tone
4. increased gastric mucous production (protects gastric epithelium)

9

3 functions of thromboxane (TXA2)

1. increased platelet aggregation
2. increased vascular tone
3. increased bronchial tone

*prostacyclin and thromboxane have opposite effecs (but prostacyclin affects uterine tone, thromboxane doesnt (("P" = messes with uterus, aka Pussy))

10

What enzyme do corticosteroids block?

Phospholipase A2

11

What are 4 COX inhibitors?

1. NSAIDS
2. Aspirin (binds irreversibly)
3. Acetaminophen
4. celecoxib (COX-2 specific)

12

What is different about acetaminophen from most COX inh.?

Inactivated peripherally, so no anti-inflammatory effects and no effects on platelet function

13

Increased bronchial tone (2)

1. leukotrienes (LTC4, LTD4)
2. thromboxane (TXA2)

14

Decreased bronchial tone (2)

1. Prostacyclin (PGI2)
2. Prostaglandin

15

Increased platelet aggregation (1)

Thromboxane

16

Decreased platelet aggregation (1)

Prostacyclin

17

Increased uterine tone (1)

Prostaglandin

18

Decreased uterine tone (1)

Prostacyclin

19

Increased vascular tone (1)

Thromboxane

20

Decreased vascular tone (2)

1. Prostaglandins
2. Prostacyclins

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