Epoxygenase
Encyclopedia
Epoxygenase is an enzyme that produces hydroxyeicosatetraenoic acids (HETEs) and epoxyeicosatrienoic acid
s (EETs) from arachidonic acid
, causing effects such as cell proliferation and decrease in cyclooxygenase
activity.
Epoxyeicosatrienoic acid
The Epoxyeicosatrienoic acids or EETs are signaling molecules formed by the action of Cytochrome P450 epoxygenase on 20-carbon essential fatty acids, such as arachidonic acid, from which it is produced by the enzyme epoxygenase....
s (EETs) from arachidonic acid
Arachidonic acid
Arachidonic acid is a polyunsaturated omega-6 fatty acid 20:4.It is the counterpart to the saturated arachidic acid found in peanut oil, Arachidonic acid (AA, sometimes ARA) is a polyunsaturated omega-6 fatty acid 20:4(ω-6).It is the counterpart to the saturated arachidic acid found in peanut oil,...
, causing effects such as cell proliferation and decrease in cyclooxygenase
Cyclooxygenase
Cyclooxygenase is an enzyme that is responsible for formation of important biological mediators called prostanoids, including prostaglandins, prostacyclin and thromboxane. Pharmacological inhibition of COX can provide relief from the symptoms of inflammation and pain...
activity.
HETEs
Hydroxyeicosatetraenoic acids cause:- In mononuclear leukocytesMononuclear leukocytesMononuclear leukocytes are white blood cells with a one-lobed nucleus. There are two main types of mononuclear leukocytes: monocytes and lymphocytes.Normal hematologic blood values of MLs are about 35% of all white blood cells....
: Cell proliferation, calciumCalciumCalcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
release from intracellular stores and decreased TNFTumor necrosis factorTumor necrosis factor is a cytokine involved in systemic inflammation and is a member of a group of cytokines that stimulate the acute phase reaction...
production. - Suggested to destruct beta cellBeta cellBeta cells are a type of cell in the pancreas located in the so-called islets of Langerhans. They make up 65-80% of the cells in the islets.-Function:...
s, contributing to type 1 diabetes - In endothelial cells: Decreased release of fibrinolytic factors and decrease binding of antithrombinAntithrombinAntithrombin is a small protein molecule that inactivates several enzymes of the coagulation system. Antithrombin is a glycoprotein produced by the liver and consists of 432 amino acids. It contains three disulfide bonds and a total of four possible glycosylation sites...
- Cell proliferation and migration of vascular smooth muscle cells, suggesting contribution to atherosclerosisAtherosclerosisAtherosclerosis is a condition in which an artery wall thickens as a result of the accumulation of fatty materials such as cholesterol...
. - VasoconstrictionVasoconstrictionVasoconstriction is the narrowing of the blood vessels resulting from contraction of the muscular wall of the vessels, particularly the large arteries, small arterioles and veins. The process is the opposite of vasodilation, the widening of blood vessels. The process is particularly important in...
, increased myogenic mechanismMyogenic mechanismThe myogenic mechanism is how arteries and arterioles react to an increase or decrease of blood pressure to keep the blood flow within the blood vessel constant....
sensitivity in renal and cerebral arteries.
EETs
Generally, EETs cause:- CalciumCalciumCalcium is the chemical element with the symbol Ca and atomic number 20. It has an atomic mass of 40.078 amu. Calcium is a soft gray alkaline earth metal, and is the fifth-most-abundant element by mass in the Earth's crust...
release from intracellular stores - Increased sodium-hydrogen antiporterSodium-hydrogen antiporterThe sodium–hydrogen antiporter or sodium–hydrogen exchanger is a membrane protein found in many cells, and especially in those of the nephron of the kidney...
activity - Increased cell proliferation
- Decreased cyclooxygenaseCyclooxygenaseCyclooxygenase is an enzyme that is responsible for formation of important biological mediators called prostanoids, including prostaglandins, prostacyclin and thromboxane. Pharmacological inhibition of COX can provide relief from the symptoms of inflammation and pain...
activity