2013-02-12 Physio Prostaglandins

Question 1

Prostaglandins belong to what class of compounds? What other molecules are in this class?

Answer 1

Prostaglandins are eicosanoids (also

Question 2

What kind of range within the body do prostaglandins acton (e.g. systemic, para-, auto-crine?)

Answer 2

LOCAL: para- and auto-crine

Question 3

What do the different components of a prostaglandin’s name mean? (e.g. EP2)

Answer 3

The first letter = ring structure; # = # of double bonds

Question 4

What is the (most common) precursor used to make eicosanoids?

Answer 4

arachadonic acid

Question 5

What type of receptors do eicosanoids bind?

Answer 5

usu. GPCRs

Question 6

What enzyme is involved in leukotriene synthesis?

Answer 6

lipoxygenases (can be blocked to treat asthma)

Question 7

prostanoids

Answer 7

category of eicosanoids incl. thromboxanes and prostaglandins; made by COX enzymes

Question 8

What controls the release of arachadonic acid?

Answer 8

phospholipase A2 (incr by inflamm/mech/neuro/hormonal stimuli)

Question 9

What pathway do inflammatory mediators use to up eicosanoid production?

Answer 9

“inflam. signals (e.g. IL-1, TNF, LPS) induce expression of COX-2 and activate phospholipase A2 (PLA2) in many cell types, leading to eicosanoid production at sites of inflammation.”

Question 10

Do eicosanoids cause pain?

Answer 10

Not directly, they are hyperalgesic (incr sensitivity to pain)

Question 11

Where do glucocorticoid drugs interfere with prostaglandin synthesis?

Answer 11

they block phospholipase A2—>decr. arachadonic acid—>decr everything downstream of that

Question 12

What are the two big classes of leukotrienes mentioned in notes? What does each do?

Answer 12

LBT4 [CHEMOTAX] and cysteinyl (LTC/LTD/LTD) [ASTHMA]

Question 13

What effect to PGE/PGI2 have on the ductus arteriosus?

Answer 13

keep it open/patent

Question 14

What is aspirin’s effect on COX enzymes? Compared to other enzymes?

Answer 14

IRREVERSIBLY inhibits COX-1 AND 2

Question 15

What’s the problem with -coxib drugs?

Answer 15

Inhibit only COX-2: blocks prostacyclin (a.k.a. PGI2) but not thromboxane A2—>incr thrombosis risk

Question 16

What effects do PGE/F have on pregnancy?

Answer 16

Prepare for birth by softening cervix and incr contractions; can be given as abortifacient; NSAIDs can prolong gestation

Question 17

What prostaglandin is gut protective? What drug inhibits it? What drug can you co-prescribe to prevent gut side-effects?

Answer 17

PGE—>inhibited by NSAIDs; pts on long-term NSAIDs can get misoprostol

Question 18

What eicosanoid causes platelet lysis?

Answer 18

prostaglandin I2 (PGI2)

Question 19

What eicosanoid causes platelet aggregation?

Answer 19

thomboxane A2 (TxA2)

Question 20

What are the leukotriene drug targets are there for asthma?

Answer 20

• inhibit lipoxygenase (zileuton);

- inhibit leukotriene C/D/E receptors (CysLT receptors) “-lukast family of drugs”