AN OVERVIEW OF THE ARACHIDONIC ACID CASCADE
Arachidonic Acid Metabolism
FREE ARACHIDONIC ACID IS RAPIDLY STORED IN NEURONAL PHOSPHOLIPIDS
Like arachidonic acid, both AEA and 2-AG are liberated from the cell membrane by phospholipases in a stimulus-dependent manner (), and are selectively oxygenated by COX2, but not COX1. COX2-mediated 2-AG oxygenation was shown to generate PGH2 glycerol esters (PGH2-G) in cultured macrophages, whereas PGH2 ethanolamides (PG-H2EA) were produced by COX2-catalized oxygenation of AEA in human fibroblasts (; ). 2-AG was metabolized by COX2 as effectively as arachidonic acid, whereas AEA oxygenation by COX2 occurs with a micromolar Km, suggesting that this reaction may only occur in tissues in which high amounts of AEA are found ().
eicosanoids; cyclooxygenase; prostaglandin H2 endoperoxidase; prostanoids; peroxides; tyrosyl radical; arachidonic acid; nonsteroideal anti‐inflammatory drugs; coxibs
ARACHIDONIC ACID METABOLISM IN THE BRAIN
Arachidonic Acid may also be an important nutrient to consider in regular supplemental doses, particularly if you do not consume animal products (red meat, organ meat, eggs) on a daily basis. Studies have shown that given somewhat comparable amounts of protein, those who consume animal products will make more progress with resistance exercise than those that do not (vegetarians). Some people have long proposed that Arachidonic Acid was the missing component in such diets, too integral to the anabolic response for lower dietary levels not to be noticed. We have also seen a good deal of empirical evidence suggesting that an Arachidonic Acid deficiency exists in many experienced bodybuilders. On a number of cases, tissue tests for the content of phospholipids have revealed unusually low levels of Arachidonic Acid in highly trained athletes. The old time bodybuilders understood the need for red meat in the diet, and often looked at this food with a sort of anabolic reverence. Even if they did not understand things like Arachidonic Acid content and the role of this nutrient in the core anabolic response, they understood it was necessary for optimal growth. Those who find their intake of animal product inadequate, a single capsule of 250 mg daily should provide a sufficient supply of this essential omega-6 fatty acid.
Several structurally different neurotransmitter receptors—including D-dopaminergic and -adrenergic—share the ability to reduce adenylyl cyclase activity and to lower cAMP levels in cells, through the intermediate of an "inhibitory" G protein (G). When transfected in CHO cells, receptors of this group produce, in addition, what appears to be a "silent" facilitation of arachidonic acid release. Namely, receptor activation has no effect, per se, on arachidonate release, but, if release is triggered by a second agent—for example, by stimulation of a different receptor or by a Ca ionophore—it will greatly potentiate it (, ). This novel form of regulation involves, like adenylyl cyclase inhibition, a G protein, as shown by the ability of pertussis toxin to inhibit the response, and of GTP--S to mimic it ().
Arachidonic acid: contents in brief - Tuscany Diet
Presentation Summary : Fatty Acid Metabolism. Can originate from dietary linoleic acid (LA), our essential fatty acid, that is desaturated and elongated to arachidonic acid (AA)
A schematic picture of the ways in which arachidonic acid and its metabolites may act in regulating neuronal activity is shown in . Arachidonic acid is released from phospholipids in cells stimulated by many first messengers, including neurotransmitters, neuromodulators, and neurohormones. The free fatty acid has, as such, a short lifespan, during which it may interact with and affect the activity of ion channels and protein kinases within the cell. Alternatively, it may be transformed to a family of metabolites—the eicosanoids—which may also produce important effects on intracellular targets. In both cases, the arachidonic acid cascade affects neuronal excitability by fulfilling the primary criteria defining a second messenger system—that is, receptor-dependent formation and intracellular site of action.
Synthesis of Arachidonic Acid - [PDF Document]
Arachidonic acid and its metabolites ..
Liberation of Arachidonic Acid and its Metabolism to Protaglandins (PG), Thromboxanes (TX)and Leukotrienes (LT)
Prostaglandins, arachidonic acid, and inflammation.
A similar preference for 15-HPETE formation is observed in singlet O2 oxidation of arachidonic acid.
Prostaglandins, arachidonic acid, and inflammation | Science
These results haveimplications for understanding the anti-inflammatory properties of n-3 fattyacids.
Arachidonic Acid Metabolism - Gravity Waves
Presentation Summary : The fatty acids react ... in small amounts in all body tissues and fluids Many physiological effects * Prostaglandin Sources Biosynthesized from arachidonic acid ...
Inflammatory Remarks about Arachidonic Acid ..
AB - Prostaglandin H synthase (PGHS) catalyzes the conversion of arachidonic acid to prostaglandin G2 in the cyclooxygenase reaction. The first step of the mechanism has been proposed to involve abstraction of the pro-S hydrogen atom from C13 to generate a pentadienyl radical spanning C11-C15. We report here the synthesis of six site-specifically deuterated arachidonic acids to investigate the structure of the radical intermediate. The preparation of these compounds was achieved using a divergent scheme that involved one advanced intermediate for all targets. The synthetic design introduced the label late in the routes and allowed the utilization of common synthetic intermediates in the preparation of various targets. Both 13(R)- and 13(S)-deuterium-labeled arachidonic acids were synthesized in high enantiomeric purity as deduced from soybean lipoxygenase assays and mass spectrometric analysis of the resulting enzymatic products. Each synthetic compound was reacted under anaerobic conditions with the wide singlet tyrosyl radical of PGHS-2 to generate a radical intermediate that was analyzed by EPR. Deuterium substitution at positions 11, 13(S), and 15 resulted in the loss of one hyperfine interaction, indicating that the protons at these positions interact with the unpaired electron. Simulation of the spectra was achieved with one set of parameters that are consistent with the assignment of a pentadienyl radical. Use of 16-[2H2]-arachidonic acid indicated that only one of the protons at C16 gives rise to a strong hyperfine interaction. The findings are discussed in the context of two proposed mechanisms for the cyclooxygenase reaction.
Synthesis of Arachidonic Acid | Request PDF
Where the eicosanoids differ from "classical" second messengers is in their ability to cross the cell membrane, diffuse through the extracellular space, and interact with high-affinity receptors located on neighboring neurons (). Eicosanoid receptors have been characterized in the brain and have been shown to be linked to second messengers, such as cyclic AMP, very much like the receptors recognized by dopamine, noradrenaline, and so on. Therefore, thanks to the ability to branch at the same time within and without a cell, the arachidonic acid cascade may give rise both to intracellular second messengers and to local mediators, bridging the gap between transmembrane and transcellular communication. This two-pronged role may be important in integrating the responses of postsynaptic neurons with the activity of presynaptic terminals and of other contacting cells.
Arachidonic acid synthesis from biodiesel-derived …
Presentation Summary : The process of inflammation initiates from tissue injury or from foreign presence ... arachidonic acid and b) platelet activating factor (PAF) IL-1, IL-6 ...
"I have always been impressed by the quick turnaround and your thoroughness. Easily the most professional essay writing service on the web."
"Your assistance and the first class service is much appreciated. My essay reads so well and without your help I'm sure I would have been marked down again on grammar and syntax."
"Thanks again for your excellent work with my assignments. No doubts you're true experts at what you do and very approachable."
"Very professional, cheap and friendly service. Thanks for writing two important essays for me, I wouldn't have written it myself because of the tight deadline."
"Thanks for your cautious eye, attention to detail and overall superb service. Thanks to you, now I am confident that I can submit my term paper on time."
"Thank you for the GREAT work you have done. Just wanted to tell that I'm very happy with my essay and will get back with more assignments soon."