Eoxin D4, also known as 14,15-
leukotriene D4
Leukotriene D4 (LTD4) is one of the leukotrienes. Its main function in the body is to induce the contraction of smooth muscle, resulting in bronchoconstriction and vasoconstriction. It also increases vascular permeability. LTD4 is released by bas ...
, is an
eoxin
Eoxins are proposed to be a family of proinflammatory eicosanoids (signaling compounds that regulate inflammatory and immune responses). They are produced by human eosinophils (a class of white blood cells), mast cells, the L1236 Reed–Sternberg c ...
. Cells make eoxins by metabolizing arachidonic acid with a
15-lipoxygenase
ALOX15 (also termed arachidonate 15-lipoxygenase, 15-lipoxygenase-1, 15-LO-1, 15-LOX-1) is, like other lipoxygenases, a seminal enzyme in the metabolism of polyunsaturated fatty acids to a wide range of physiologically and pathologically importa ...
enzyme to form
15(''S'')-hydroperoxyeicosapentaenoic acid (i.e. 15(''S'')-HpETE). This product is then converted serially to eoxin A4 (i.e.
EXA4
Eoxin A4, also known as 14,15-leukotriene A4, is an eoxin. Cells make eoxins by metabolizing arachidonic acid with a 15-lipoxygenase enzyme to form 15(''S'')-hydroperoxyeicosapentaenoic acid (i.e. 15(''S'')-HpETE). This product is then converted ...
), EXC4,
EXD4
Eoxin D4, also known as 14,15-leukotriene D4, is an eoxin. Cells make eoxins by metabolizing arachidonic acid with a 15-lipoxygenase enzyme to form 15(''S'')-hydroperoxyeicosapentaenoic acid (i.e. 15(''S'')-HpETE). This product is then converted ...
, and
EXE4
Eoxin E4, also known as 14,15-leukotriene E4, is an eoxin. Cells make eoxins by metabolizing arachidonic acid with a 15-lipoxygenase enzyme to form 15(''S'')-hydroperoxyeicosapentaenoic acid (i.e. 15(''S'')-HpETE). This product is then converted ...
by
LTC4 synthase
Leukotriene C4 synthase is an enzyme that in humans is encoded by the ''LTC4S'' gene.
The protein encoded by this gene, LTC4S (or glutathione S-transferase II) is an enzyme that converts leukotriene A4 and glutathione to create leukotriene C4. Th ...
, an unidentified
gamma-glutamyltransferase
Gamma-glutamyltransferase (also γ-glutamyltransferase, GGT, gamma-GT, gamma-glutamyl transpeptidase; ) is a transferase (a type of enzyme) that catalyzes the transfer of gamma-glutamyl functional groups from molecules such as glutathione to ...
, and an unidentified
dipeptidase
Dipeptidases are enzymes secreted by enterocytes into the small intestine. Dipeptidases hydrolyze bound pairs of amino acids, called dipeptides.
Dipeptidases are secreted onto the brush border of the villi in the small intestine, where they cleave ...
, respectively, in a pathway which appears similar if not identical to the pathway which forms leukotreines, i.e.
LTA4
Leukotriene A4 (LTA4) is a leukotriene, and is the precursor for the productions of LTB4 ( leukotriene B)) and LTC4 (leukotriene C4).
Biosynthesis of Leukotriene A4
Following the biosynthesis of eicosanoid, triggered as a result of infection o ...
,
LTC4
Leukotriene C4 (LTC4) is a leukotriene. LTC4 has been extensively studied in the context of allergy and asthma. In cells of myeloid origin such as mast cells, its biosynthesis is orchestrated by translocation to the nuclear envelope along with c ...
,
LTD4
Leukotriene D4 (LTD4) is one of the leukotrienes. Its main function in the body is to induce the contraction of smooth muscle, resulting in bronchoconstriction and vasoconstriction. It also increases vascular permeability. LTD4 is released by bas ...
, and
LTE4
Leukotriene E4 (LTE4) is a cysteinyl leukotriene involved in inflammation. It is known to be produced by several types of white blood cells, including eosinophils, mast cells, tissue macrophages, and basophils, and recently was also found to be ...
. This pathway is schematically shown as follows:
EXA
4 is viewed as an intracellular-bound, short-lived intermediate which is rapidly metabolized to the down-stream eoxins. The eoxins down stream of EXA4 are secreted from their parent cells and, it is proposed but not yet proven, serve to regulate allergic responses and the development of certain cancers (see
Eoxins
Eoxins are proposed to be a family of proinflammatory eicosanoids (signaling compounds that regulate inflammatory and immune responses). They are produced by human eosinophils (a class of white blood cells), mast cells, the L1236 Reed–Sternberg c ...
).
References
Eicosanoids
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