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16 Cards in this Set
- Front
- Back
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Give a general definition of eicosanoids.
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Eicosanoids are small molecules made from membrane-derived, polyunsaturated C20 fatty acids (ie: arachadonic acid) that have potent physiological and pharmacological activities.
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What causes eicosanoid synthesis?
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Extracellular stimuli: hormones, proteases, injury, neural excitation, muscular activity
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Do eicosanoids act in an autocrine, paracrine, or endocrine manner?
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Local: autocrine and paracrine
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What is the general mechansim by which eicosanoids act?
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They bind to cell surface receptors and stimulate signal transduction.
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Give some examples of physiological functions triggered by eicosanoids (there are eleven listed).
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1. Pain and fever
2. Swelling and inflammation 3. Smooth muscle contraction 4. Smooth muscle relaxation 5. Platelet aggregation 6. Allergy and immediate hypersensitivity 7. WBC functions 8. Secretion 9. Cell growth 10. Chemotaxis 11. Ion transport |
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Name four fatty acid precursors to eicosanoids (hint: all are C20).
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1. Arachidonic acid
2. Dihomo gamma-linolenic acid 3. Eicosatetraenoic acid 4. Eicosapentaenoic acid |
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Where do the fatty acid precursors to eicosanoids come from?
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They are derived from linolenic (omega-3) and linoleic (omega-6) acids.
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What are the three major pathways of eicosanoid synthesis?
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1. Cyclooxygenase (COX)
2. Lipoxygenase (LOX) 3. Cytochrome P-450 |
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On which carbon are all prostaglandins modified?
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C15
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Which eicosanoids are active in blood clotting?
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Thromboxanes
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Which eicosanoid synthesis pathway produces leukotrienes?
Name some major functions of leukotrienes. |
Leukotrienes are products of the LOX pathway.
They are involved in inflammation, asthma, edema, bronchoconstriction, and anaphylaxis. |
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Which eicosanoid synthesis pathway produces lipoxins?
Name some major functions of lipoxins. |
Lipoxins are products of the LOX pathway.
They are involved in chemotaxis, cell migration, cell adhesion, wound healing, anti-inflammation, vasodilation, degranulation, and NK cell inhibition. |
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In what tissues are eicosanoids found?
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Eicosanoids are found in all tissues except RBCs.
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Name the two major types of products that come from the COX pathway.
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1. Prostaglandins
2. Thromboxanes |
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Name the three major types of products that come from the LOX pathway.
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1. Leukotrienes
2. Lipoxins 3. HPETE, HETE, dihydroxy-HETE |
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Name the two major types of products that come from the cyt P-450 pathway.
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1. 16-, 17-, 18-, 19-, 20-HETE
2. EETs (5,6-EET and 11,12-EET) |
