Eicosanoids Flashcards
What are the two parts of the COX reaction?
Oxygenase - where NSAIDs act
Peroxidase
Different between COX-1 and COX-2?
COX-1 is expressed in many tissues constantly, COX-2 is expressed during inflammation and has a larger cyclooxygenase binding pocket.
What are the precursors of eicosanoids?
Phospholipase A2 cleave Arachidonic Acid
What is the determining step of Leukotriene synthesis and what can block it?
5-Lipoxygenase converts AA to LTA4. Blocked by Zileuton
What does Zileuton do and what is it used for?
Blocks 5-LOX from producing Cysteinyl Leukotriene, used for preventing asthma symptoms.
What is a competitive antagonist of cysteinyl leukotrienes?
Zafirlukast. Blocks the Leukotriene receptors, used for chronic asthma prevention.
What are the differences between LTB4, LTC4, LTD4, LTE4?
LTB4 - causes chemotaxis
LTC4, LTD4, and LTE4 - Cysteinyl Leukotrienes
How does the body use Eicosanoids?
Locally in tissues, rapidly broken down in the lungs 95% first pass.
What are prostaglandin’s role in pain and fever?
PGE2 and PGI2, lower threshold for pain.
PGE2 is produced in the hypothalamus to change the thermoregulation point after IL1/TNFalpha are detected.
What are effects in Platelets and endothelium?
TXA2 - induces platelet aggregation - permanently for that platelet
Endothelium - PGI2 inhibits platelet aggregation
How do prostaglandins play a role in fetus development?
PGE2 keeps the ductus arteriosus patent. COX-2 and EP4 receptor in the fetus.
Role in pregnancy and uterus?
PGI2 - keeps uterus from contracting
PGE2 - initiates labor, cervical ripening
Role in nonpregnant uterus?
PGF2alpha, causes contraction of the uterus, reason for primary dysmenorrhea.
What are the effects in the kidney?
PGE2 and PGI2 promote renal blood flow and diuresis
What is used for cervical ripening and termination of early pregnancy?
Dinoprostone. (PGE2)
Side effect of uterine rupture
What is used for replacement protective prostaglandins in treating gastric ulcers?
Misoprostol (PGE1)
When can Misoprostol not be used?
Contraindicated in pregnancy, due to inducing labor.
What can be used to control post partum hemorrhage?
Carboprost (PGF2alpha). Also used for termination of early pregnancy.
What is a drug used for IM erectile dysfunction?
Alprostadil. (PGE1)
What drug would be given to maintain a ductus arteriosus?
Alprostadil (PGE1)
What drug would be given to help with primary pulmonary hypertension?
Epoprostenol (PGI2)
How does Bimatoprost help with glaucoma?
Increased outflow of aqueous humor.
What drug is used cosmetically for eye lash hypotrichosis?
Bimatoprost, grows eye lashes.
