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34 Cards in this Set
- Front
- Back
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What is the main phospholipase that breaks down phospholipids to arachidonic acid?
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Phospholipase A2
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Which enzymes are targets for nonsteroidal drugs?
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COX I and COX2
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What are the four metabolic pathways that arachidonic acid can undergo?
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1) lipoxygenases to give leukotrienes; 2) cyclooxygenases to give prostaglandins and thromboxanes; 3) epoxygenases (microsomal P450 monooxygenases) to give epoxides; 4) free radicals to give isoprostanes
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Where do corticosteroids act?
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On the phospholipase (they are phospholipase inhibitors). They prevent release of fatty acids.
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Where do NSAIDs act?
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On cyclooxygenases.
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What does dietary supplementation do?
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It changes composition of fatty acids.
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What does colchicine do?
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It blocks the downstream effectors of phagocyte attraction, activation (from leukotrienes; LTB4) and prevents inflammation from occurring.
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What are some essential fatty acids?
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Linoleic acid and linolenic acid.
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What are some normal sources that are high in omega six?
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1) corn, 2) safflower, 3) chicken, 4) pork
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What foods are rich in omega three fatty acids?
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1) flax oil; 2) nut oils; 3) phytoplankton
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For all the prostaglandins, R1 always has the....
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....carboxyl group.
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prostaglandins (PGA-PGF) characteristic
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a single five membered ring
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endoperoxides (intermediate characteristic)
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a bridged bicycle with an O-O bond
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Prostacyclins (GPI) characteristic
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two fused five membered rings
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thromboxanes (TXA)
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a bridged bicycle (one 6 membered ring)
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FOr prostaglandins, prostacyclins, and thromboxanes: the numbers imply particular types and locations of double bonds...what does 1 mean?
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trans 13, 14 alkene
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What does the 2 mean?
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cis 5,6; trans 13, 14 diene
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What does the 3 mean?
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cis 5,6; trans 13,14; cis 17,18 triene
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What are the common intermediates of prostaglandins, prostacyclins, and thromboxanes?
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PGG2, PGH2
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What is the function of cyclooxygenases (COX)?
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They are bifunctional enzymes: simultaneously (1) cyclizes and (2) peroxidizes in its enzyme activity
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What inhibits COX?
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NSAIDs
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COX activity can be inhibited by?
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aspirin and NSAIDs
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What kind of effects does PGI2 have?
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1) poweful vasodilator; 2) inhibitor of platelet aggregation; 3) constricts smooth muscle in GI tract (if have a COX inhibitor all these things will go down) --> think PGI2 is a result of a certain stress
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Where does thromboxane synthesis usually occur?
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1) In platelets (converts PGH to TXA); 2) it enhances platelet aggregation; 3) Therefore, if we use NSAID to block COX then thromboxane goes down and therefore platelet aggregation also goes down
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What is a characteristic of TxA2?
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It is very unstable, so it will convert to TxB2.
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Lipoxygenases enzymes are most active in...
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1) platelets and 2) leukocytes
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LTB4 attracts (leukotrienes LTB series) ...
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...neutrophils (inflammation effects).
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What are LTC4 and LTD4 known as?
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(1) the slow reacting substance of anaphylaxis; important in: (2) asthma [constricts bronchiole smooth muscle], (3) anaphylaxis, (4) allergic rhinitis; (5) attracts eosinophils
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Feeding omega-3 fatty acids leads to production of what PG?
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PG3 (not PG2)
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Dihomo gamma-linolenic acid leads to production of what PG?
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PG1
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Arachidonic acid leads to production of what PG?
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PG2
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Adding omega 3 FA to diet is shown to decrease the risk of....
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(1) heart attack; (2) stroke; (3) other cardiovascular diseases; (4) modulate autoimmune diseases; (5) arthritis (less joint swelling); (6) asthma
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It is thought that gamma linoleic acid is a omega 6 fatty acid that can...
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...(1) be used for arthritis; (2) or to modulate fat deficiencies in older women
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Name of a synthetic eicosanoid
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Dinoprostone
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