The 5-Lipoxygenase as a Common Pathway for Pathological Brain and Vascular Aging
Figure 1
Schematic representation of the 5-Lipoxygenase enzyme metabolic pathway. Arachidonic acid is released from diacyglycerol or membrane phospholipids via the action of Phospholipase . Once free, arachidonic acid is oxidized by 5-lipoxygenase (5-LO), which has been activated by the Five-Lipoxygenase-Activating-Protein (FLAP), at carbon 5 to form the unstable 5-hydroxy-peroxy-eicosatetraenoic acid (5HPETE), which is promptly metabolized into the more stable 5-hydroxy-eicosatetraneoic acid (5HETE). The 5HETE can then be converted in leukotriene A4 (LTA4), which can serve either as an intracellular intermediate in the synthesis of LTB4 and LTC4, or may be released extracellularly and subsequently be taken up by adjacent cells devoid of 5-LO activity but expressing LTA4-hydrolase and/or LTC4 synthase.
