Prostaglandins

Question 1

Eicosanoids

Answer 1

enzyme derived products of arachadonic acid

Question 2

eicosanoids catalyzed by cyclooxygenase

Answer 2

Prostanoids

Question 3

five types of prostanoids

Answer 3

PGD2, PGE1/2, PGF2a, PGI2, TXA2

Question 4

isoeicosanoids

Answer 4

free radical catalyzed products of AA

Question 5

arachadonic acid (AA)

Answer 5

one of the fatty acids that makes up the phospholipid bilayer

Question 6

phospholipase A2 (PLA2)

Answer 6

required for the release of AA from cell membranes

Question 7

role of COX in AA pathway

Answer 7

converts free AA to an intermediary compound that is rapidly converted by isomerases and syntheses into prostanoids

Question 8

what enzyme converts intermediate into TxA2?

Answer 8

thromboxane synthase (in platelets)

Question 9

what enzyme converts intermediate into PGE2?

Answer 9

PGE2 isomerase (in GI endothelial cells)

Question 10

what enzyme converts intermediate to PGI2?

Answer 10

PGI2 isomerase (in vascular endothelial cells)

Question 11

activation of PLA2

Answer 11

by diverse stimuli such as inflammation, chemical, and physical stimuli

Question 12

two forms of PLA2

Answer 12

cytosolic and inducible

Question 13

cytosolic PLA2

Answer 13

constitutive, present in concentrations high enough for regulatory functions of the cell.

Question 14

inducible PLA2

Answer 14

activated in setting of inflammation or cancer. responsible for greater proportion of free AA in these conditions

Question 15

isoforms of COX

Answer 15

COX1 (constitutively) and COX2 (inducible)

Question 16

expression of COX1

Answer 16

constitutive. but does contribute some degree of prostanoid formation during inflammation

Question 17

expression of COX2

Answer 17

expressed in times of inflammation and cancer

Question 18

function of COX1

Answer 18

housekeeping functions: cytoprotective in GI, platelet function

Question 19

what cells only express COX1?

Answer 19

platelets

Question 20

tissue distribution of COX1

Answer 20

broad distribution

Question 21

what induces COX2 up regulation?

Answer 21

inflammatory stimuli, cytokines, growth factor, tumor promoters

Question 22

COX2 is the predominant isoform in what cells?

Answer 22

endothelial cells

Question 23

distribution of COX2

Answer 23

kidney, brain, synovial cells, macrophages, monocytes

Question 24

what down regulates COX2

Answer 24

glucocorticoid

Question 25

cellular mechanism of action of prostanoids

Answer 25

GPCR binding specific to prostaglandin activates second messenger system

Question 26

catabolism of prostanoids

Answer 26

made quickly and degraded quickly. use as drugs is therefore limited unless made into stable analogs

Question 27

what cells produce TxA2

Answer 27

platelets, macrophages, kidney parenchymal cells

Question 28

COX isoform responsible for TxA2

Answer 28

COX1

Question 29

TxA2 activity

Answer 29

induces platelet aggregation, vasoconstriction and smooth muscle cell proliferation

Question 30

where is prostacyclin I2 (PGI2) produced?

Answer 30

endothelial cells

Question 31

COX isoform for PGI2

Answer 31

COX2

Question 32

activity of PGI2

Answer 32

inhibits platelet aggregation and smooth muscle cell proliferation, vasodilates, proinflammatory

Question 33

role of prostaglandin E (PGE1/2)

Answer 33

cytoprotection in the GI by inhibition of gastric acid secretion (COX1), regulates renal blood flow via vasodilation (COX2), regulates salt via renin (COX2), induces uterine/GI smooth muscle contraction (COX1/2), cryogenic role for body temp (COX1/2), pro inflammatory effects (COX2)

Question 34

role of prostaglandin F2a (PGF2a)

Answer 34

induces vascular smooth muscle and uterine contraction (luteal regression), vasoconstriction (COX1/2)

Question 35

role of PGD2

Answer 35

cutaneous dilation, inhibits platelet aggregation, promotes sleep, mast cell product, chemotaxis of Th2, hair follicles

Question 36

role of inflammation in prostanoid release

Answer 36

increases sPLA2, which increases AA release, which increases prostanoid production via increased COX2 expression

Question 37

prostanoids involved in dolor

Answer 37

nocioception: PGE1/2, PGI2

Question 38

prostanoids involved in rubor

Answer 38

vasodilation: PGE1/2, PGI2

Question 39

prostanoids involved in calor

Answer 39

fever: PGE1/2

Question 40

prostanoids involved in tumor

Answer 40

vasodilation, edema, leukocyte infiltration, chemotaxis: PGI2, PGE2, PGD

Question 41

steroids

Answer 41

reduce the release ofAA from cell membrane by targeting PLA2

Question 42

NSAIDs

Answer 42

reduce the production of intermediary compounds by targeting COX

Question 43

Ridogrel

Answer 43

reduces production of TxA2 by targeting thromboxane synthase

Question 44

antagonist to prostanoid

Answer 44

none known

Question 45

carbaprost

Answer 45

PGF2 analog used as abortifacient, post-partum bleeding to expel placenta

Question 46

misoprostol

Answer 46

PGE analogue used as abortifacient and for gastric cytoprotection

Question 47

dinoprostone

Answer 47

PGE analogue used to induce labor

Question 48

treatment for PDA

Answer 48

PGE analog