|
Neuroprostanes
The neuroprostanes are prostaglandin-like compounds formed ''in vivo'' from the free radical-catalyzed peroxidation of essential fatty acids (primarily docosahexaenoic acid) without the direct action of cyclooxygenase (COX) enzymes. The result is the formation of isoprostane-like compounds F4-, D4-, E4-, A4-, and J4-neuroprostanes which have been shown to be produced in vivo. These oxygenated essential fatty acids possess potent biological activity as anti-inflammatory mediators inhibiting the response of human macrophages that augment the perception of pain. See also *Isoprostanes *Prostaglandin The prostaglandins (PG) are a group of physiologically active lipid compounds called eicosanoids having diverse hormone-like effects in animals. Prostaglandins have been found in almost every tissue in humans and other animals. They are derive ... References Prostaglandins {{biochem-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Isoprostanes
The isoprostanes are prostaglandin-like compounds formed ''in vivo'' from the free radical-catalyzed peroxidation of essential fatty acids (primarily arachidonic acid) without the direct action of cyclooxygenase (COX) enzymes. The compounds were discovered in 1990 by L. Jackson Roberts and Jason D. Morrow in the Division of Clinical Pharmacology at Vanderbilt University. These nonclassical eicosanoids possess potent biological activity as inflammatory mediators that augment the perception of pain. These compounds are accurate markers of lipid peroxidation in both animal and human models of oxidative stress. Elevated levels of isoprostanes are suspected of contributing to increased risk of heart attack in patients taking Coxibs. Isoprostanes and their metabolites have also been shown to be elevated in the urine of cigarette smokers, and have been suggested as biomarkers of oxidative stress in smokers. Abundance Polyunsaturated fatty acids other than arachidonic acid are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prostaglandin
The prostaglandins (PG) are a group of physiologically active lipid compounds called eicosanoids having diverse hormone-like effects in animals. Prostaglandins have been found in almost every tissue in humans and other animals. They are derived enzymatically from the fatty acid arachidonic acid. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring. They are a subclass of eicosanoids and of the prostanoid class of fatty acid derivatives. The structural differences between prostaglandins account for their different biological activities. A given prostaglandin may have different and even opposite effects in different tissues in some cases. The ability of the same prostaglandin to stimulate a reaction in one tissue and inhibit the same reaction in another tissue is determined by the type of receptor to which the prostaglandin binds. They act as autocrine or paracrine factors with their target cells present in the immediate vicinity of the site of their secret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lipid Peroxidation
Lipid peroxidation is the chain of reactions of oxidative degradation of lipids. It is the process in which radical (chemistry), free radicals "steal" electrons from the lipids in cell membranes, resulting in cell damage. This process proceeds by a free radical chain reaction#Chemical chain reactions, chain reaction mechanism. It most often affects polyunsaturated fatty acids, because they contain multiple double bonds in between which lie methylene bridges (-CH2-) that possess especially reactive hydrogen atoms. As with any radical reaction, the reaction consists of three major steps: initiation, propagation, and termination. The chemical products of this oxidation are known as lipid peroxides or lipid oxidation products (LOPs). Initiation Initiation is the step in which a fatty acid radical (chemistry), radical is produced. The most notable initiators in living cells are reactive oxygen species (ROS), such as hydroxyl radical, OH· and hydroperoxyl, HOO·, which combines wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Essential Fatty Acid
Essential fatty acids, or EFAs, are fatty acids that humans and other animals must ingest because the body requires them for good health but cannot synthesize them. Only two fatty acids are known to be essential for humans: alpha-linolenic acid (an omega-3 fatty acid) and linoleic acid (an omega-6 fatty acid). These are supplied to the body both as the free fatty acid or more commonly as some glyceride derivative. Deficiency in these fatty acids is rare. These fatty acids are essential because they are precursors to vitamins, cofactors. These derivatives include prostaglandins, leukotrienes, thromboxanes, lipoxins, and others. When the two EFAs were discovered in 1923, they were designated "vitamin F", but in 1929, research on rats showed that the two EFAs are better classified as fats rather than vitamins. Functions :''The biological effects of the ω-3 and ω-6 fatty acids are mediated by their mutual interactions, see Essential fatty acid interactions for detail.'' In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Docosahexaenoic Acid
Docosahexaenoic acid (DHA) is an omega-3 fatty acid that is a primary structural component of the human brain, cerebral cortex, skin, and retina. In physiological literature, it is given the name 22:6(n-3). It can be synthesized from alpha-linolenic acid or obtained directly from maternal milk (breast milk), fatty fish, fish oil, or algae oil. DHA's structure is a carboxylic acid (-''oic acid'') with a 22-carbon chain (''docosa-'' derives from the Ancient Greek for 22) and six (''hexa-'') ''cis'' double bonds (''-en-''); with the first double bond located at the third carbon from the omega end. Its trivial name is cervonic acid (from the Latin word ''cerebrum'' for "brain"), its systematic name is ''all-cis''-docosa-4,7,10,13,16,19-hexa-enoic acid, and its shorthand name is 22:6(n−3) in the nomenclature of fatty acids. Most of the docosahexaenoic acid in fish and multi-cellular organisms with access to cold-water oceanic foods originates from photosynthetic and heterotroph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclooxygenase
Cyclooxygenase (COX), officially known as prostaglandin-endoperoxide synthase (PTGS), is an enzyme (specifically, a family of isozymes, ) that is responsible for formation of prostanoids, including thromboxane and prostaglandins such as prostacyclin, from arachidonic acid. A member of the animal-type heme peroxidase family, it is also known as prostaglandin G/H synthase. The specific reaction catalyzed is the conversion from arachidonic acid to prostaglandin H2 via a short-living prostaglandin G2 intermediate. Pharmaceutical inhibition of COX can provide relief from the symptoms of inflammation and pain. Nonsteroidal anti-inflammatory drugs (NSAIDs), such as aspirin and ibuprofen, exert their effects through inhibition of COX. Those that are specific to the COX-2 isozyme are called COX-2 inhibitors. The active metabolite (AM404) of paracetamol is a COX inhibitor, a fact to which some or all of its therapeutic effect has been attributed. In medicine, the root symbol "COX" is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anti-inflammatory
Anti-inflammatory is the property of a substance or treatment that reduces inflammation or swelling. Anti-inflammatory drugs, also called anti-inflammatories, make up about half of analgesics. These drugs remedy pain by reducing inflammation as opposed to opioids, which affect the central nervous system to block pain signaling to the brain. Nonsteroidal anti-inflammatory drugs Nonsteroidal anti-inflammatory drugs (NSAIDs) alleviate pain by counteracting the cyclooxygenase (COX) enzyme. On its own, COX enzyme synthesizes prostaglandins, creating inflammation. In whole, the NSAIDs prevent the prostaglandins from ever being synthesized, reducing or eliminating the inflammation and resulting pain. Some common examples of NSAIDs are aspirin, ibuprofen, and naproxen. The newer specific COX-inhibitors are not classified together with the traditional NSAIDs, even though they presumably share the same mode of action. On the other hand, there are analgesics that are commonly associat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pain
Pain is a distressing feeling often caused by intense or damaging stimuli. The International Association for the Study of Pain defines pain as "an unpleasant sensory and emotional experience associated with, or resembling that associated with, actual or potential tissue damage." In medical diagnosis, pain is regarded as a symptom of an underlying condition. Pain motivates the individual to withdraw from damaging situations, to protect a damaged body part while it heals, and to avoid similar experiences in the future. Most pain resolves once the noxious stimulus is removed and the body has healed, but it may persist despite removal of the stimulus and apparent healing of the body. Sometimes pain arises in the absence of any detectable stimulus, damage or disease. Pain is the most common reason for physician consultation in most developed countries. It is a major symptom in many medical conditions, and can interfere with a person's quality of life and general functioning. Simple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prostaglandin
The prostaglandins (PG) are a group of physiologically active lipid compounds called eicosanoids having diverse hormone-like effects in animals. Prostaglandins have been found in almost every tissue in humans and other animals. They are derived enzymatically from the fatty acid arachidonic acid. Every prostaglandin contains 20 carbon atoms, including a 5-carbon ring. They are a subclass of eicosanoids and of the prostanoid class of fatty acid derivatives. The structural differences between prostaglandins account for their different biological activities. A given prostaglandin may have different and even opposite effects in different tissues in some cases. The ability of the same prostaglandin to stimulate a reaction in one tissue and inhibit the same reaction in another tissue is determined by the type of receptor to which the prostaglandin binds. They act as autocrine or paracrine factors with their target cells present in the immediate vicinity of the site of their secret ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
