Biochem - Unit II - PG

  1. Discover and distinguish relationships between different types of eicosanoid molecules (PGs, TXs, LTs)
    • PGs have 5-member ring
    • TXs and LTs don't

    LTs have three conjugated double-bonds
  2. Gain knowledge of enzymes that create PGs and TXs (COX-1 and -2)
  3. Explore physiological functions of these molecules
  4. Ascertain how pharmacological inhibitors work to block activity
  5. eicosanoid
    • all 20C compounds
    • paracrine, hormone-like
  6. prostaglandin
    • virtually sysnthesized in all cells
    • 20C
    • 5-member ring
    • short half-life, not stored
    • work locally
  7. synthesis of prostaglandin
    • COX1/COX2: arachidonic acid -> PGH2
    • two catalytic functions:
    • cyclization
    • peroxidation

    Prostaglandin synthases: PGH2-> PGE2,PGD2,...
  8. COX1 vs COX2
    • constitutive vs. inducible
    • maintaining homeostasis vs. inflammatory response
    • all cells vs. immunocells
    • not affected by steroids or bacteria vs. induced by cytokine, inhibited by steroids
  9. _______ stimulate constriction and clotting of platelets. Conversely, ____ is produced to have the opposite effect on the walls of blood vessels where clots should not be forming.
    • thromboxanes
    • PGI2
  10. Certain prostaglandins (i.e. ___) are involved with induction of labor by inducing uterine contractions.
  11. Prostaglandins are involved in several other organs
    • -regulate salt and fluid balance in body
    • -increase blood flow in kidneys
    • -increase secretion of protective GI mucus
    • -inhibit GI acid synthesis
    • -leukotrienes, related molecules, promote constriction of bronchi associated with asthma
  12. NSAIDs
    • Inhibit COX enzymes
    • Reduce production of prostaglandins and thromboxanes
    • Reduce pain, fever and inflammation
  13. Aspirin
    • - works on both COX-1 and COX-2
    • - acetyl group of aspirin binds to serine in COX, blocking its activity
    • - ”nonselective”
    • [same with ibuprofen]
  14. Low dose aspirin therapy:
    • - Aspirin irreversibly inhibits COX-1 (and COX-2)
    • - Has a short half-life & New platelets are constantly being made
    • - Will therefore reduce but not abolish the ability for blood to clot, thereby reducing heart attacks and stroke
  15. Selective COX-2 inhibitor
    • Coxibs
    • Celebrex (celecoxib)
  16. The dietary precursor of eicosanoids is ________.
    the essential fatty acid, linoleic acid
  17. ___________ are known as eicosanoids.
    Prostaglandins, thromboxanes and leukotrienes
Card Set
Biochem - Unit II - PG
Biochem - Unit II - PG - Lutz