Eicosanoids/Prostanoids

Question 1

What are eicosanoids/prostanoids derived from and what is the enzyme that acts to release this precursor?

Answer 1

arachidonic acid; phospholipase A₂

Question 2

What are the general functions of eicosanoids/prostanoids?

Answer 2

• Inflammatory Process: pain, fever, swelling, redness
• Other Function:
  
  • regulate local blood pressure
  • blood clotting
  • possibly labor
  • maybe sleep/wake cycles

Question 3

What enzymes convert arachidonic acid to prostaglandins?

Answer 3

cyclooxygenases

Question 4

What enzymes convert arachidonic acid to thromboxanes?

Answer 4

cyclooxygenases

Question 5

What enzymes convert arachidonic acid to leukotrienes?

Answer 5

lipoxygenases

Question 6

What are general functions of prostaglandins?

Answer 6

• vasodilation/constriction, blood flow
• platelet aggregation
• blood pressure
• inflammatory response (swelling, pain, fever, redness)
• other cell processes

Question 7

Prostacyclin

Answer 7

• vasodilatory
• increases blood flow
• reduces blood pressure
• opposes platelet aggregation

Question 8

PGE₂

Answer 8

• can stimulate/oppose vascular contraction
• can increase blood flow
• can increase microvessel permeability → swelling
• leads to pain, possible fever

Question 9

PGF_2a

Answer 9

• contracts smooth muscle
• can induce labor

Question 10

TBX_A2

Answer 10

• potent platelet aggregator
• local vasoconstrictor

Question 11

Leukotrienes

Answer 11

• represent slow substance of anaphylaxis
• mediate reactive airway disease

Question 12

How are NSAIDs related to prostaglandins?

Answer 12

• NSAIDs reduce pain, swelling, and fever by inhibiting various COX enzymes, affecting prostaglandins and thromboxanes