The resulting 5-HPETE yields the unstable allylic epoxide substrate LTA4 which is quickly hydrolyzed by the LTA4H (leukotriene A4 hydrolase) enzyme to produce LTB4, or synthesized by LTC4S (leukotriene C4 synthase) with the addition of glutathione to produce LTC4 which can be further metabolized to produce LTD4 (leukotriene D4) and LTE4 (leukotriene E4). The lipooxygenase pathway is one of several possible pathways including the cyclooxygenase pathway (also PGH synthase pathway), isoprostane pathway, and cytochrome P450 epoxygenases pathway following the arachidonic acid metabolism, but is the only pathway in which the subsequent steps will lead to the production of leukotrienes.
The resulting 5-HPETE produces the unstable allylic epoxide substrate LTA4, which is rapidly hydrolyzed by the enzyme LTA4H to produce LTB4 or synthesized by LTC4S with glutathione addition to produce LTC4, which can be further metabolized into LTD4 and LTE4. The lipooxygenase pathway is one of several possible pathways following arachidonic acid metabolism, including the cyclooxygenase pathway.