TBL - prostaglandins Flashcards
What are eicosanoids?
Polunsaturated, oxygenated derivatives of C20 fatty acids
Prostaglandins are eicosanoids. True or false?
True
What are the three C20 fatty acids that prostaglandins are derivatives of?
Arachidonic acid
DLGA
EPA
What are prostaglandins classified according to?
the code of ring variants and the number of double bonds in their side chain
What are the R1 and R2 functional groups of PGE2?
R1 - =O
R2 - -OH
What are the R1 and R2 functional groups of PGD2?
R1 - OH
R2 - =O
What are the R1 and R2 functional groups of PGF2a?
R1 - -OH
R2 - -OH
PGD2 are produced during an inflammatory response. True or false?
False - during an immune response
PGE2 are produced during an inflammatory response. True or false?
True
Which PG is produced during vasoconstriction?
PGF2a
Prostacyclin is an eicosanoid. True or false?
True
What is the role of prostacyclin in relation to platelets?
It is a potent vasodilator that inhibits platelet aggregation
What is the role of thromboxane A2 in relation to platelets?
It is an inducer of platelet aggregation
How many fatty acids are PGs made from?
20 carbon
Arachidonic acid gives rise to which series of PG?
PGE2
DGLA gives rise to which series of PG?
PGE1
EPA gives rise to which series of PG?
PGE3
A minimum of how many double bonds are needed to form a PG?
2
What are the two essential fatty acids for our body?
Omega 3 and omega 6
COX metabolises arachidonic acid to a precursor. Which group of drugs block the action of COX?
NSAIDs e.g. aspirin
What frees arachidonic acid from the cell membranes?
Phospholipase A2
COX2 pathway is activated upon a physiological stimuli. True or false?
False - COX1 is activated
What sort of stimuli activates the COX2 pathway?
A pathological stimulus
At increased levels, prostaglandins make cells behave abnormally. True or false?
True
Which COX pathway results in the synthesis of pro-inflammatory PGs?
COX2
Which COX pathway results in the production of thromboxane A2 and PGI2?
COX 1
Prostaglandins are involved in renal function. True or false?
True
Prostaglandins are involved in bone remodelling. True or false?
True
How many types of prostaglandin receptors are there?
5
What are prostaglandin receptors called?
P receptors
PG receptors are ligand-gated ion channels. True or false?
False - G-protein couple transmembrane receptors
PG receptors are linked to cAMP and Na+ signalling. True or false?
False - cAMP and Ca2+
What type of PGs do DP receptors bind?
PGD2
What physiological significance does the binding of PGD2 to DP receptors have?
Vasodilation
GI relaxation
inhibition of platelet aggregation
What type of PG binds to FP receptor?
PGF2a
What physiological significance does the binding of PGF2a to FP receptor have?
Bronchoconstriction
Luteolysis
The IP receptor bind PGI2. What does the binding to this receptor mediate?
Vasodilation
Inhibition of platelet aggregation
Fibrinolysis
What binds to the TP receptor?
TXA2
What does the binding of TXA2 to TP receptor mediate?
Vasoconstriction
Platelet aggregation
Bronchoconstriction
EP1 receptor mediates GI contraction and pyrexia. True or false?
True
What does the EP2 receptor mediate?
Bronchodilation
Vasodilation
Stimulates GI fluid secretion
What does the EP3 receptor mediate?
GI relaxation
inhibition of gastric acid secretion
Inhibition of of autonomic nervous system transmitters
Pyrexia
What do EP4 receptors mediate?
Vasodilation
Bone homeostasis
Pyrexia
Arachidonic acid is involved in the omega 6 pathway. True or false?
True
What starts the omega 3 pathway off?
a- linoleic acid
In the omega 6 pathway what follows on from linoleic acid?
GLA -> DGLA -> AA
What starts the omega 6 pathway?
linoleic acid
DHA is involved in the omega 3 pathway. True or false?
True
EPA is found in the omega 6 pathway. True or false?
True
EPA and DHA are found in plants. True or false?
False - oily fish are rich in EPA and DHA
Fishy oil supplementation produces a dose-dependent increase of fasting blood TG but not total, HDL or LDL cholesterol in hyperlipidaemic subjects. True or false?
False - reduction in fasting blood TG
LCPUFA are critical for infant and childhood brain development. True or false?
True
DHA and EPA are high in western diets so no supplementation is required early on in life. True or false?
False - low in western diet so consider supplementation
A reduction in PGI2 via use of NSAIDs leads to hypokalaemia and acute renal failure. True or false?
False - hyperkalaemia
A reduction in PGE2 leads to increase in sodium retention, peripheral oedema, hypertension, increase in weight. True or false?
True
Arthrotec is a composition of which two drugs?
Diclofenac and misoprostol
How do prostaglandin analogues work in glaucoma?
They reduce intra-ocular pressure relieving the optic nerve; allowing fluid to drain freely
Latanoprost and bimatoprost are what types of PG analogues?
PGF2a
