What are the products of lipoxygenase pathway?
Major products: it metabolizes arachidonic acid to 5-hydroperoxy-eicostetraeoic acid (5-HpETE) which is converted to 1) 5-Hydroxyicosatetraenoic acid (5-HETE) and then to 5-oxo-eicosatetraenoic acid (5-oxo-ETE), 2) leukotriene A4 (LTA4) which may then be converted to leukotriene B4 (LTB4) or Leukotriene C4 (LTC4) (LTC4 …
What does 5-lipoxygenase activating protein do?
5-Lipoxygenase-activating protein (FLAP) is an 18-kDa integral membrane protein which is essential for cellular leukotriene (LT) synthesis, and is the target of LT biosynthesis inhibitors.
What is the function of lipoxygenase?
Lipoxygenases are non-heme iron enzymes that catalyze the dioxygenation of polyunsaturated fatty acids, yielding hydroperoxides. The first crystal structures have recently been published, revealing an unusual iron site.
What is cyclooxygenase and lipoxygenase?
Cyclooxygenase- and lipoxygenase-catalyzed arachidonic. acid metabolism. Two major metabolic routes, i.e., the COX and LOX pathways, control the biosynthesis of eicosanoids.
Where does the arachidonic acid pathway occur?
Distribution. Arachidonic acid is naturally found incorporated in the structural phospholipids in the cell membrane in the body or stored within lipid bodies in immune cells [13]. It is particularly abundant in skeletal muscle, brain, liver, spleen and retina phospholipids [14].
How is arachidonic acid produced in an inflammatory pathway?
Arachidonic acid is a polyunsaturated fatty acid covalently bound in esterified form in the cell membranes of most body cells. Following irritation or injury, arachidonic acid is released and oxygenated by enzyme systems leading to the formation of an important group of inflammatory mediators, the eicosanoids.
What does leukotriene B4 do?
Leukotriene B4 induces recruitment and activation of neutrophils, monocytes and eosinophils. It also stimulates the production of a number of proinflammatory cytokines and mediators indicating an ability to augment and prolong tissue inflammation.
What induces cyclooxygenase?
Cyclooxygenase (Cox)-2 is a prostaglandin synthesis enzyme that plays a key role in inflammation in fish4,5. Cox-2 is expressed at low levels in resting cells and can be markedly induced by lipid peroxides, as well as pro-inflammatory and mitogenic stimuli6,7,8,9.
What are COX-1 and COX-2 pathways?
COX-1 is thought to be responsible for the production of prostaglandins associated with normal physiologic function and is found in such tissues as the stomach, kidney, and platelets. COX-2 was thought to be induced as the result of inflammation and responsible for producing prostaglandins such as prostaglandin E2.