TBL - Prostaglandins Flashcards
What are the three main Pg substrates?
AA
DGLA
EPA
What is AA?
Arachidonic Acid
Gives rise to 2 series
What is DGLA
Dihomogamma-linolenic acid
Gives rise to 1 series
What is EPA?
Eicosapentaenoic Acid
Gives rise to 3 series
PG biosynthesis summary
arachidonic avid liberated by phospholipase A2
Arachidonate converted to parent PGs by COX 1 or 2
Parent PGs rapidly catalysed to inactive metabolites
Prostaglandins are involved in:
Fever generation Ovulation,fertilisation, parturition GI Function Renal function Carcinogenesis Bone remodelling Sleep Inflammation and pain Allergy and immunity Vascular homeostasis and haemostasis
What frees AA from membranes
Phospholipase A2
DP mediates
Vasodilation
Inhibits platelet aggregation
GI I relaxation
FP mediates
Luteolysis
Bronchoconstriction
IP mediates
Vasoconstriction
Inhibits platelet aggregation
Fibrinolysis
TP mediates
Vasoconstriction
Platelet aggregation
Bronchoconstriction
EP1 mediates
GI contraction
Pyrexia
EP2 mediates
Bronchodilation
Vasodilation
Stimulates GI fluid secretion
EP3 mediates
GI relaxation
Inhibits gastric acid secretion
Inhibits ANS transmitters
Pyrexia
EP4 mediates
Vasodilation
Bone homeostasis
Pyrexia
What is athrotec made up of?
Diclofenac+misoprostol
What is misoprostol?
EP 1/3 agonist
Restores cytoprotection
Prevents stomach ulcers
What is E2 responsible for?
Inflammation
What is D2 responsible for
Immunity
What is F2 responsible for
Vasoconstriction
What is PGI2
Prostacyclin
A potent vasodilator that inhibits platelet aggregation
What is TXA2
Thromboxane
Inducer of platelet aggregation
What does the COX-1 pathway do?
Reduce platelet aggregation
Decrease AA-induced inflammation
Sensitive to radiation injury
Resistant to indomethacin-induce gastric ulceration
What does the COX-2 pathways do?
Defective ovulation, fertilization, implantation, decidualization
Decreased brain injury induced by ischemia
Suppression of tumourgenesis
Renal nephropathy
Cardiac fibrosis
Peritonitis
Failure of patent ductus arteriosus closure
