Prostaglandins (Younger) Flashcards
What can cause an asthmatic episode?
Leukotrienes
Prostaglandins and related compounds (leukotrienes and thromboxanes) are all collectively called ______.
Eicosanoids
Eicosanoids differ from hormones by these 4 ways:
synthesized in all cells
act locally (not systemically)
extremely short half-lives
extremely small concentration to elicit a desired effect
This promotes the likelihood of blood coagulation. Specific example of a prostaglandin?
Procoagulant, thromboxane
Endothelial cells play what role in blood coagulation:
Anticoagulant/ Vaso Dilation / (eicosanoid: prostacyclin )
Platelets play what role in blood coagulation:
Vasoconstriction/ procoagulant/ (eicosanoid: thromboxane)
What is the most common precursor of eicosanoids
Arachidonic acid
What is activated to release Arachidonic acid?
Phospholipase A2
What enzyme is used to make leukotrienes (asthma assoc) from arachidonic acid?
Lipoxygenase
What enzyme is used to make prostacyclin and thromboxanes?
Cyclooxygenase
2 important enzyme targets for anti-inflammatory drugs:
Phospholipase A2 (blocks synthesis of arachidonic acid) Cyclooxygenase (NSAIDS- Non steroidal anti inflammatory drugs)
What is a steroidal anti-inflammatory drug that is used to minimize inflammatory reactions?
Glucocorticoids- reduces discomfort with inflammation (promotes inhibition of phospholipase A2)
What are COX1 and COX2?
They are enzymes that mediate pain, heat, redness, swelling.
NSAIDS (Aspirin) are targeting what as inhibitors?
NSAIDS like aspirin etc. target COX1 and COX2 of cyclooxygenase
What might happen as a result of blocking the cyclooxgenase step in eicosanoid metabolism?
Increased leukotrienes (which can induce an asthmatic response)
Aspirin is a ________ inhibitor of cyclooxygenase?
suicide
Platelets under aspirin control can they synthesize new cyclooxygenase?
no they can’t synthesize new cyclooxygenase because they have no nucleus
True/False: Aspirin inhibition only lasts a few days in platelets, they will regenerate more cyclooxygenase.
False, aspirin inhibits it until the platelet dies.
Endothelial cells have a nucleus so they can synthesize new ___________.
Cyclooxygenase and prostacyclin
Aspirin does what big picture with risk of heart disease?
Reduces the risk of un-wanted blood clotting in those with increased risk of cardiovascular disease
Endothelial cells release ______ into blood plasma.
prostacyclin
Plasma prostacyclin binds to receptors which activate _____ systems on platelets.
cAMP, which release granules to promote thromboxane release from arachidonic acid leading to aggregating agents being released and COAGULATION
If you inhibit the 2 Cox enzymes (COX 2 inducible and COX1 constitutive) it permits the back-flow into making more _______?
Leukotrienes
