12-Hydroxy-5,8,10,14-eicosatetraenoic Acid
A lipoxygenase metabolite of ARACHIDONIC ACID. It is a highly selective ligand used to label mu-opioid receptors in both membranes and tissue sections. The 12-S-HETE analog has been reported to augment tumor cell metastatic potential through activation of protein kinase C. (J Pharmacol Exp Ther 1995; 274(3):1545-51; J Natl Cancer Inst 1994; 86(15):1145-51)
Hydroxyeicosatetraenoic Acids
Eicosatetraenoic acids substituted in any position by one or more hydroxy groups. They are important intermediates in a series of biosynthetic processes leading from arachidonic acid to a number of biologically active compounds such as prostaglandins, thromboxanes, and leukotrienes.
Arachidonic Acids
Arachidonic acids are polyunsaturated fatty acids, specifically a type of omega-6 fatty acid, that are essential for human nutrition and play crucial roles in various biological processes, including inflammation, immunity, and cell signaling. They serve as precursors to eicosanoids, which are hormone-like substances that mediate a wide range of physiological responses.
Lipoxygenase
Arachidonate Lipoxygenases
Enzymes catalyzing the oxidation of arachidonic acid to hydroperoxyarachidonates. These products are then rapidly converted by a peroxidase to hydroxyeicosatetraenoic acids. The positional specificity of the enzyme reaction varies from tissue to tissue. The final lipoxygenase pathway leads to the leukotrienes. EC 1.13.11.- .
Leukotrienes
A family of biologically active compounds derived from arachidonic acid by oxidative metabolism through the 5-lipoxygenase pathway. They participate in host defense reactions and pathophysiological conditions such as immediate hypersensitivity and inflammation. They have potent actions on many essential organs and systems, including the cardiovascular, pulmonary, and central nervous system as well as the gastrointestinal tract and the immune system.
Leukotriene B4
The major metabolite in neutrophil polymorphonuclear leukocytes. It stimulates polymorphonuclear cell function (degranulation, formation of oxygen-centered free radicals, arachidonic acid release, and metabolism). (From Dictionary of Prostaglandins and Related Compounds, 1990)
Leukotriene A4
(2S-(2 alpha,3 beta(1E,3E,5Z,8Z)))-3-(1,3,5,8-Tetradecatetraenyl)oxiranebutanoic acid. An unstable allylic epoxide, formed from the immediate precursor 5-HPETE via the stereospecific removal of a proton at C-10 and dehydration. Its biological actions are determined primarily by its metabolites, i.e., LEUKOTRIENE B4 and cysteinyl-leukotrienes. Alternatively, leukotriene A4 is converted into LEUKOTRIENE C4 by glutathione-S-transferase or into 5,6-di-HETE by the epoxide-hydrolase. (From Dictionary of Prostaglandins and Related Compounds, 1990)
Arachidonic Acid
An unsaturated, essential fatty acid. It is found in animal and human fat as well as in the liver, brain, and glandular organs, and is a constituent of animal phosphatides. It is formed by the synthesis from dietary linoleic acid and is a precursor in the biosynthesis of prostaglandins, thromboxanes, and leukotrienes.
Prostaglandins B
Physiologically active prostaglandins found in many tissues and organs. They are potent pressor substances and have many other physiological activities.
Arachidonate 5-Lipoxygenase
An enzyme that catalyzes the oxidation of arachidonic acid to yield 5-hydroperoxyarachidonate (5-HPETE) which is rapidly converted by a peroxidase to 5-hydroxy-6,8,11,14-eicosatetraenoate (5-HETE). The 5-hydroperoxides are preferentially formed in leukocytes.
Arachidonate 12-Lipoxygenase
An enzyme that catalyzes the oxidation of arachidonic acid to yield 12-hydroperoxyarachidonate (12-HPETE) which is itself rapidly converted by a peroxidase to 12-hydroxy-5,8,10,14-eicosatetraenoate (12-HETE). The 12-hydroperoxides are preferentially formed in PLATELETS.
Lipid Peroxides
Peroxides produced in the presence of a free radical by the oxidation of unsaturated fatty acids in the cell in the presence of molecular oxygen. The formation of lipid peroxides results in the destruction of the original lipid leading to the loss of integrity of the membranes. They therefore cause a variety of toxic effects in vivo and their formation is considered a pathological process in biological systems. Their formation can be inhibited by antioxidants, such as vitamin E, structural separation or low oxygen tension.
Lipoxygenase Inhibitors
Compounds that bind to and inhibit that enzymatic activity of LIPOXYGENASES. Included under this category are inhibitors that are specific for lipoxygenase subtypes and act to reduce the production of LEUKOTRIENES.
Eicosanoids
A class of compounds named after and generally derived from C20 fatty acids (EICOSANOIC ACIDS) that includes PROSTAGLANDINS; LEUKOTRIENES; THROMBOXANES, and HYDROXYEICOSATETRAENOIC ACIDS. They have hormone-like effects mediated by specialized receptors (RECEPTORS, EICOSANOID).
Neutrophils
Chromatography, High Pressure Liquid
Receptors, Leukotriene B4
A class of cell surface leukotriene receptors with a preference for leukotriene B4. Leukotriene B4 receptor activation influences chemotaxis, chemokinesis, adherence, enzyme release, oxidative bursts, and degranulation in polymorphonuclear leukocytes. There are at least two subtypes of these receptors. Some actions are mediated through the inositol phosphate and diacylglycerol second messenger systems.
Gas Chromatography-Mass Spectrometry
A microanalytical technique combining mass spectrometry and gas chromatography for the qualitative as well as quantitative determinations of compounds.
Calcimycin
An ionophorous, polyether antibiotic from Streptomyces chartreusensis. It binds and transports CALCIUM and other divalent cations across membranes and uncouples oxidative phosphorylation while inhibiting ATPase of rat liver mitochondria. The substance is used mostly as a biochemical tool to study the role of divalent cations in various biological systems.
Fatty Acids, Unsaturated
Seminal Vesicles
8,11,14-Eicosatrienoic Acid
A 20-carbon-chain fatty acid, unsaturated at positions 8, 11, and 14. It differs from arachidonic acid, 5,8,11,14-eicosatetraenoic acid, only at position 5.
Peroxides
A group of compounds that contain a bivalent O-O group, i.e., the oxygen atoms are univalent. They can either be inorganic or organic in nature. Such compounds release atomic (nascent) oxygen readily. Thus they are strong oxidizing agents and fire hazards when in contact with combustible materials, especially under high-temperature conditions. The chief industrial uses of peroxides are as oxidizing agents, bleaching agents, and initiators of polymerization. (From Hawley's Condensed Chemical Dictionary, 11th ed)
Blood Platelets
Microsomes
Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)
Stereoisomerism
Spectrophotometry, Ultraviolet
Chemotactic Factors
Prostaglandins
A group of compounds derived from unsaturated 20-carbon fatty acids, primarily arachidonic acid, via the cyclooxygenase pathway. They are extremely potent mediators of a diverse group of physiological processes.
Prostaglandin-Endoperoxide Synthases
Enzyme complexes that catalyze the formation of PROSTAGLANDINS from the appropriate unsaturated FATTY ACIDS, molecular OXYGEN, and a reduced acceptor.
Chromatography, Thin Layer
Indomethacin
A non-steroidal anti-inflammatory agent (NSAID) that inhibits the enzyme cyclooxygenase necessary for the formation of prostaglandins and other autacoids. It also inhibits the motility of polymorphonuclear leukocytes.
Eosinophils
Mass Spectrometry
Cytosol
Oxidation-Reduction
A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).
5,8,11,14-Eicosatetraynoic Acid
A 20-carbon unsaturated fatty acid containing 4 alkyne bonds. It inhibits the enzymatic conversion of arachidonic acid to prostaglandins E(2) and F(2a).
Rabbits
Substrate Specificity
Dose-Response Relationship, Drug
Calcium
A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.
Receptors, Eicosanoid
Cell surface proteins that bind eicosanoids with high affinity and trigger intracellular changes influencing the behavior of cells. Among the eicosanoid receptors are receptors for the prostaglandins, thromboxanes, and leukotrienes.