Compared with other lipid mediators of inflammation, such as those generated from the cyclooxygenase or lipoxy genase pathways, paf has a wider range of. Platelets interact with several coagulation factors, while the coagulation product thrombin is a potent platelet activating agonist. Platelet activating factor paf generated by an igemediated reaction in the peritoneal cabity of rats was partially purified by adsorption to diatomaceous earth. Increased platelet activating factor levels in chronic. Role of platelet activating factor paf in the intestinal epithelial secretory and chinese hamster ovary cho cell cytoskeletal responses to cholera toxin.
Cholesterol synthesis inhibitors protect against platelet. Plateletactivating factor paf, 10alkyl2acetylsn glycero3phosphocholine is a potent biological mediator that exerts its effects in a variety of cells and. Pdf platelet activating factor and crohns disease 5. This gene encodes platelet activating factor acetylhydrolase isoform 2, a singlesubunit intracellular enzyme that catalyzes the removal of the acetyl group at the sn2 position of platelet activating factor identified as 1.
Characterization of a plateletactivating factor receptor. Plateletactivating factor paf, 10alkyl2acetylsnglycero3phosphocholine is a potent mediator of inflammation that causes neutrophil activation, increased vascular permeability, vasodilation, and bronchoconstriction in addition to platelet activation. Platelet activating factor acetylhydrolase 2, cytoplasmic is an enzyme that in humans is encoded by the pafah2 gene. The effect of pure synthetic paf 10alkyl2acetylsnglycero3 phosphorylcholine was studied in human platelets. Alternatively, you can download the file locally and open with any standalone pdf reader.
Platelet activating factor receptor the platelet activating factor receptor is a gprotein coupled receptor which binds platelet activating factor. Targetspecific elisa kits are available from a variety of manufacturers. Platelet activating factor, also known as paf, pafacether or agepc acetylglyceryletherphosphorylcholine, is a potent phospholipid activator and mediator of many leukocyte functions, platelet aggregation and degranulation, inflammation, and anaphylaxis. Platelet activating factorplatelet activating factor. This file contains additional information, probably added from the digital camera or scanner used to create or digitize it. Paf is a potent phospholipid activator and mediator of many leukocyte functions, including platelet aggregation, inflammation, and anaphylaxis. Platelet activating factor receptor pafr responds to platelet activating factor paf, a phospholipid mediator of celltocell communication that exhibits diverse physiological effects. Plateletactivating factor activates cardiac gk via. Supporting information behavior of platelet activating. It is released from multiple cells of the immune system, such as eosinophils, neutrophils, and mast. Paf is synthesized through other metabolic routes as well 119, and elicits its actions through a paf receptor.
Regulation of platelet activating factor synthesis. The plateletactivating factor receptor is a gprotein coupled receptor which binds platelet activating factor the paf receptor shows structural characteristics of the rhodopsin mim 180380 gene family and binds platelet activating factor paf. The inactive stereoisomer, dpaf, was not effective in lowering plasma tnf. Plateletactivating factor legal definition of platelet. Coagulation factors, phosphatidylserine, platelet receptors, thrombin summary platelet activation and blood coagulation are complementary, mutually dependent processes in haemostasis and thrombosis. In an allergic reaction, during the release of mediators, one of the key molecules is paf. When l platelet activating factor paf or alprazolam a paf antagonist was administered to lipopolysaccharide lpstreated mice, the level of plasma tumor necrosis factor tnf.
Plateletactivating factor an overview sciencedirect topics. Plateletactivating factor paf is a mediator of inflammation that is implicated in cvd and hiv1 infection, shares mechanisms of immune. Plateletactivating factor stimulates cytokine production by. Detailed annotation on the structure, function, physiology, pharmacology and clinical relevance of drug targets. Plateletactivating factor financial definition of platelet. The role of plateletactivating factor in chronic inflammation. This complex regulates the amount of a molecule called platelet activating factor paf in the brain. Plateletactivating factor, paf acetylhydrolase, and. Platelet activating factor paf is a lipid mediator involved in several allergic reactions. In this study, patients with anaphylactic reactions were found to have. Plateletactivating factor paf, 1oalkyl2acetylsnglycero3phosphocholine is a biologically active phospholipid mediator. The effect of paf and its antagonists was further intensively studied in vitro on isolated platelets, leucocytes, macrophages and endothelial cells.
Paf was originally described as a soluble factor in blood, so it is apparent that some cells secrete it following synthesis. Paf acts largely by binding to its receptor, pafr, a gprotein coupled receptor found on a variety of cells, including cells of the immune system. Platelet activating factor paf is a potent inflammatory mediator that mimics many of the features of asthma, including eosinophil recruitment and activation and induction of ahr. Platelet activating factor paf is an endogenous, active phospholipid released from inflammatory cells, platelets, and endothelial cells, and is involved in the regulation of immune responses.
Synthesis of plateletactivating factor by polymorphonuclear. May 12, 2014 platelet activating factor pafplatelet activating factor paf introductionintroduction chemical and structural formulaechemical and structural formulae significancesignificance synthesis and metabolism. A minute, nonnucleated, disklike cytoplasmic body found in the blood plasma of mammals that is derived from a megakaryocyte and functions to promote. Platelet activating factor binds to a unique gprotein coupled seven transmembrane receptor and triggers multiple intracellular signaling pathways. Full text full text is available as a scanned copy of the original print version. Platelet activating factor paf is implicated in the neuronal damage that accompanies ischemia, prion disease and alzheimers disease ad. Definition of plateletactivating factor paf in the financial dictionary by free online english dictionary and encyclopedia. Paf has been shown to be involved in human reproduction, including ovulation, implantation, maturation of the fetal lung, and parturition narahara et al. Paf is formed by a smaller number of cell types than the eicosanoids, mainly leukocytes, platelets, and endothelial cells. Platelet activating factor paf lipids, which are associated with cad, have recently been linked with novel proposed etiopathological mechanisms for depression such as inflammation, oxidativenitrosative stress, and vascular endothelial dysfunction. If the file has been modified from its original state, some details such as the timestamp may not fully reflect those of the original file. Plateletactivating factor, paf acetylhydrolase, and severe. However, we found that the paf made by endothelial cells is.
Inflammation and platelet activating factor production during hepatic ischemiareperfusion weiguo zhou,l mark 0. The pafah1b1 gene also known as lis1 provides instructions for making a protein that is one part subunit of a complex called platelet activating factor acetyl hydrolase 1b pafah1b. Platelet activating factor paf is a potent phospholipid mediator, which has previously reported biological activities in bc progression and osteoclast differentiation by activating its receptor. Targetspecific elisa kits are available from a variety of manufacturers and can help streamline your immunodetection experiments. Plateletactivating factor receptor pafr is a g q g 11coupledprotein receptor that has a role in a wide range of biological processes such as vasodilation, superoxide formation, cell proliferation, angiogenesis and regulation of the inflammatory response. Platelet activating factor paf is a phospholipid that has been implicated in the pathogenesis of glomerulonephritis and can be synthesized by glomerular cells in response to different stimuli. Platelet activating factor paf is one of the most potent lipid messengers involved in a variety of physiological events. This medical animation explains platelet activating factor paf and its normal and pathologic influences on the human body. It has a role as a betaadrenergic antagonist, an antihypertensive agent, a bronchoconstrictor agent, a hematologic agent and a vasodilator agent. Lifespan biosciences currently sells 12 elisa kits, 1 protein specific for paf platelet activating factor. Platelet activating factor paf is an anaphylactic mediator that is degraded in the blood by the enzyme paf acetylhydrolase. Find out information about platelet activating factor. Blockades of phospholipase a2 and platelet activating factor receptors reduce the hemocyte phagocytosis in rhodnius prolixus.
It is one of several paf acetylhydrolases function. Plateletactivating factorpaf is a potent lipid mediator of inflammation and asthma. Platelet activating factor paf is a potent autocoid mediator implicated in a diverse range of human pathologies including shock, ischemia, asthma, cardiac and systemic anaphylaxis, cns and renal disorders, and a variety of inflammatory conditions. Paf increases glomerular permeability to proteins and urinary paf has been determined to be of renal origin. Platelet activating factor mediates angiotensin tiinduced proteinuria in isolated perfused rat kidney. This file contains additional information such as exif metadata which may have been added by the digital camera, scanner, or software program used to create or digitize it.
Pdf plateletactivating factor mediates angiotensin ti. The platelet activating factor paf signaling cascade in. The cardiovascular protective effects of yangambin, a novel and specific naturallyoccurring platelet activating factor paf receptor antagonist, were investigated in the pentobarbital anesthetized and artificially ventilated rat. Platelet activating factor, lyso platelet activating factor, and alkyl acyl glycerophosphocholine, were determined in colonic mucosal biopsies in patients with acute crohns disease, during. Physiological and pathophysiological effects of paf. Effect of plateletactivating factor paf on human platelets. The plateletactivating factor paf signaling cascade consists of paf and paflike lipids pafll that are specific, structurallydefined ligands for a gprotein coupled receptor, the paf receptor pafr, which has restricted expression on key target cells of the inflammatory, immune, and hemostatic systems. Definition of platelet activating factor in the legal dictionary by free online english dictionary and encyclopedia. Lpcat1 and lpcat2 are not only involved in pc remodeling activity but also involved in production of platelet activating factor paf 17,42, a. Using a receptor preparation of rabbit platelet membranes, we identified a. A phospholipid released by leukocytes that causes aggregation of platelets and other effects, such as an increase in vascular permeability and. Meaning of plateletactivating factor paf as a finance term. The role of plateletactivating factor in inflammation.
Plateletactivating factor paf financial definition of. N methyl d aspartate nmda receptor activation by glutamate leads to phospholipase a2 pla2 activation and the generation of platelet activating factor paf and of arachidonic acid. This period saw a burst in research activity focused predominantly on the effect of paf in various organs. The rapid ecdependent pmn adhesion initiated in minutes that occurs when the ecs are stimulated by thrombin is temporally coupled with the accumulation of platelet activating factor, a biologically active phosphoglyceride that remains associated with ecs and that activates pmns by binding to a cell surface receptor. What does plateletactivating factor paf mean in finance. Platelet activating factor synonyms, platelet activating factor pronunciation, platelet activating factor translation, english dictionary definition of platelet activating factor. Plateletactivating factor paf definition of platelet. Pafr is activated by paf and its metabolically stable. Platelet activating factor receptor acts to limit colitis. Platelet activating factor 1oalkyl2acetylsnglycero3phosphocholine.
Plateletactivating factor or a plateletactivating factor. The single platelet activating factor receptor pafr is a gprotein coupled receptor present in the plasma and nuclear membranes of the majority of cells of the vascular and innate immune system that activates a variety of pathways involved in inflammation, oncogenic transformation, tumor growth, angiogenesis and metastasis. Pdf increased levels of plateletactivating factor in. The acetyl group at the sn2 position of its glycerol backbone is essential for its biological activity, and its deacetylation induces loss of activity. Degradation of paf by paf acetylhydrolase pafah has been shown to be associated with anaphylaxis, asthma, and peanut allergy. It aggregated rat platelets and, as a consequence, activated hageman factor in in vitro, as well as in vivo, conditions. Platelet activating factor paf, a potent phospholipid activator of inflammation that signals through its cognate receptor platelet activating factor receptor, ptafr, has been shown to induce preterm delivery in mice.
Get a printable copy pdf file of the complete article 316k, or click on a page image below to browse page by page. Jan 17, 2015 platelet activating factors by aisha siddiqui 1. Plateletactivating factor receptor introduction bps. Biosynthesis of plateletactivating factor in human. Media in category platelet activating factor the following 4 files are in this category, out of 4 total.
Platelet activating factor, the trigger of haemostatic. Pdf plateletactivating factor and related lipid mediators. Murphy veterans memorial hospital, san antonio, texas 78284 the role of platelet activating factor as a potential. If you do not see its contents the file may be temporarily unavailable at the journal website or you do not have a pdf plugin installed and enabled in your browser. Emphasis is given on recent results about a new class of the socalled metalbased inhibitors of paf. Liver inflammation is a common extraintestinal manifestation in inflammatory bowel disease ibd, yet, the mechanisms driving gut. There are paf receptors both from the mast cell itself as well as over the inflammatory pathway. The possible role of platelet activating factor paf in superior mesenteric artery occlusion induced circulatory collapse was studied in anesthetized dogs. Paf is a phospholipid 10alkyl2acetylsnglycero3phosphorylcholine that has been implicated as a mediator in diverse pathologic processes. The single plateletactivating factor receptor pafr is a gprotein coupled receptor present in the plasma and nuclear membranes of the majority of cells of the vascular and innate immune system that activates a variety of pathways involved in inflammation, oncogenic transformation, tumor growth, angiogenesis and metastasis.
Meaning of platelet activating factor as a legal term. Pdf the role of plateletactivating factor in mesangial. Plateletactivating factor paf is a potent autocoid mediator implicated in a diverse range of human pathologies including shock, ischemia, asthma, cardiac and systemic anaphylaxis, cns and renal disorders, and a variety of inflammatory conditions. Platelet activating factors are associated with depressive. Endothelial cellassociated plateletactivating factor. Since some epidemiological studies demonstrate that statins, drugs that reduce cholesterol synthesis, have a beneficial effect on mild ad, we examined the effects of two cholesterol synthesis inhibitors on neuronal responses to paf. Plateletactivating factor paf is a potent inflammatory mediator that mimics many of the features of asthma, including eosinophil recruitment and activation and. Plateletactivating factor an overview sciencedirect. Langmuir monolayer study complemented with grazing incidence xray diffraction and brewster angle microscopy michal flasinski, marcin broniatowski, pawel wydro, katarzyna hacwydro, patrycja dynarowiczlatka. The role of platelet activating factor in allergic. Urinary excretion of plateletactivating factor in human and. Platelet activating factor paf is a phospholipid mediator of inflammation that is released early in inflammation by a variety of cell types. Get a printable copy pdf file of the complete article 242k. If the file has been modified from its original state, some details may not fully reflect the modified file.
Full text is available as a scanned copy of the original print version. Media in category platelet activating factor acetylhydrolase the following 7 files are in this category, out of 7 total. This article is an open access publication abstract tumor cellinduced platelet aggregation facilitates hematogenous metastasis by promoting tumor embolization. Preparations of platelet activating factor paf derived by methanolic extraction of supernatants from antigenchallenged rabbit basophils proved capable of activating platelets while concurrently inhibiting neutrophil aggregationsecretion stimulated by biologically active fmet peptides, ionophore a23187, or zymosantreated serum. The pafinduced kach channel activation was blocked by web2086, a pafreceptor inhibitor, indicating that the.
At first, results of organic compounds natural and synthetic ones and specific and nonspecific as inhibitors of paf are reported. Platelet activating factor paf platelet activating factor paf introductionintroduction chemical and structural formulaechemical and structural formulae significancesignificance synthesis and metabolism. Paf acts by binding to a unique g proteincoupled seven transmembrane receptor pafr and activates multiple intracellular signalling pathways by coupling to the g q11 and g io families of g proteins. Establishment of pafr mice confirmed that the paf receptor is re sponsible for proinflammatory responses, but that its roles in other settings remain to be. Plateletactivating factor, also known as paf, pafacether or agepc acetylglyceryletherphosphorylcholine, is a potent phospholipid activator and mediator of many leukocyte functions, platelet aggregation and degranulation, inflammation, and anaphylaxis.
The ginsenosides are also believed to have the potential to inhibit platelet activating factor. Plateletactivating factor the journal of lipid research. Platelet activating factor paf is a low molecular weight, etherlinked phospholipid originally identified as a soluble factor, released from sensitized rabbit basophils during ige anaphylaxis, that was capable of aggregating rabbit platelets 1, 2. Structural basis for signal recognition and transduction. Plateletactivating factor pafantagonists of natural. The role of plateletactivating factor in mesangial pathophysiology article pdf available in american journal of pathology 1854 february 2015 with 29 reads how we measure reads.
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