| Question |
Answer |
| What are the 3 main type of eicosanoids? |
Prostaglandins, thromboxins, leukotrienes |
| What is meant by autocrine factor? |
it releases hormones that affect itself |
| What is meant by paracranine factor? |
it releases hormones that affects nearby cells |
| What are the 3 main functions of eicosanoids? |
Inflammatory response, smooth muscle contraction |
| Eicosanoids affect smooth muscle contraction in what organs? |
intestine, bronchioles, blood vessels, pregnant uterus |
| What is the most common precursor of Eicosanoids? |
Arachidonate |
| What is a PUFA? |
poly unsaturated fatty acid |
| What are the main dietary PUFAs? |
linoleate or alpha-linoleate |
| What enzyme initiates eicosanoid production? |
phospholipase A2 |
| What is the primary FA released by PLA2? |
arachidonic acid |
| What pathway from arachidonic acid produce prostaglandins and thromboxins? |
cycloxygenase (COX) |
| What structural features are essential for biological activity in a prostaglandin? |
trans-C13 and hydroxy-C15 |
| What molecules lead from PL to thromboxin or prostaglandins? |
Arachidonate, PGG2/PGH2 |
| What is the role of TXA2? |
platelet aggregation, vasoconstriction, lymphocyte proliferation, bronchoconstriction |
| What is the role of PGI2? |
vasodilation, inhibit platelet aggregation |
| What cyclo-oxygenase is more specific for inflammation and pain? |
COX-2 |
| What inhibits COX-1? |
Non-steroidal anti-inflammatory drugs |
| What drug irreversibly inhibits COX? |
aspirin; acetylsalicylate |
| What are effects of COX-1 inhibition toxicity? |
gastric dysfunction and renal dysfunction |
| What is the role of PGA2? |
inhibits acid secretion in intestinal cells |
| What is the role of PGE2? |
regulates water and Na+ reabsorption in the kidneys, vasodilation, inhibit IL-1 and IL-2 (inflammation) |
| What reaction do steroidal anti-inflammatory drugs inhibit? |
PLA2: phospholipase A2 |
| What is the major inhibitory reaction of non-steroidal anti-inflammatory drugs? |
COX enzymes |
| Arachidonic acid released by PLA2 is eicosanoid by what 3 different ways? |
COX, lipoxygenase, cytochrome P450 |
| Draw PGA, PGD, PGE, PGF-alpha, PGG/PGH, PGI |
see slide 16 |
| Functions of PGI2 |
vasodilation (inc. cAMP) |
| Functions of PGD2 |
vasodilation, IL-1 and IL-2 (inflammation)inhibitors, attractant for eosinophils (asthma) |
| Functions of PGF2 |
vasoconstriction, bronchoconstriction, smooth muscle contraction |
| How do omega-3 fatty acids work? |
form TXA3 instead of TXA2, significantly less active platelet aggregator |
| What 2 things are required to inactivate prostaglandins? |
oxidation of 15-OH |
| The lipoxygenase pathway occurs in mainly what kind of cell type? |
leukocytes |
| What is LOX? |
lipoxygenase enzymes |
| What form of HPETE is the main precursor for most leukotrienes? |
5-HPETE |
| 5-HPETE is converted into what in the leukotriene pathway? via what enzyme? |
Leukotriene A4 via LTA4 synthase |
| Hydrolysis of LTA4 yields what product? |
LTB4 |
| What are the functions of LTB4? |
chemotactic agents for eosinophils and neutrophils, inflammatory response, vascular permeability (edema), increase IL-1 IL-2 |
| What is added to LTA4 to get LTC4? |
addition of GSH (glutathione) |
| What happens from LTC4, to LTD4, to LTE4? |
cleavage of gamma-glutamate and glycine |
| What are the functions of LTC4 and LTD4? |
increase bronchoconstriction, vascular permeability, anaphylaxis |
| What is SRS-A? What molecules make it up? |
Slow-Reacting Substance of Anaphylaxis |
| What is LXA4? How is it formed? |
lipoxin A4, arachidonic acid, 15-lipoxygenase, 5-lipoxygenase, reduction |
| What are the actions of lipoxins? |
potent inhibitors of acute inflammation |
| What does the cytochrome P450 pathway produce from arachidonate? |
epoxides, 5,6-EET, 5,6-diHETE |
| What is 5,6-EET? |
endogenous pulmonary vasodilator |
HHS Shrek
