Role of platelet activating factor paf in the initiation of the decidual reaction in the rat in reproduction. Plateletactivating factor an overview sciencedirect topics. 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. To generate paf, phospholipase a 2 removes fatty acid in the sn2 position of the estertype membrane phospholipid, followed by acetylation. Plateletactivating factor paf is a potent inflammatory mediator that mimics many of the features of asthma, including eosinophil recruitment and activation and induction of ahr. Forty years since the structural elucidation of plateletactivating. Paf was originally described as a soluble factor in blood, so it is apparent that some cells secrete it following synthesis. Pdf cardiovascular effects of plateletactivating factor. Initial release from internal source and subsequent a sustained influx. Urinary excretion of plateletactivating factor in human. Platelet activating factor paf, 10alkyl2acetylsnglycero3phosphocholine is a potent mediator of inflammation that causes neutrophil activation, increased vascular permeability, vasodilation, and bronchoconstriction in addition to platelet activation. Plateletactivating factor paf is the commonly used name for a group of potent. Plateletactivating factor paf is a potent, bioactive phospholipid that acts on multiple cells and tissues through its g proteincoupled receptor gpcr. Forty years since the structural elucidation of platelet.
Plateletactivating factor apotentchemotactic andchemokineticfactorfor humaneosinophils a. Egido 0 2 0 fundacion jimenez diaz, avda reyes catolicos 2, 28040 madrid, spain 1 pediatric renal unit, hospital 12 octubre, madrid, spain 2 renal unit, fundacion. The bioactivity of paf is effectively and tightly regulated by paf. Pdf on nov 1, 1990, s m prescott and others published plateletactivating factor find, read and cite all the research you need on. The synthesis, transport, and degradation of paf are tightly regulated, and the biochemical basis for many of these processes has been elucidated in recent years. Platelet activating factor acetylglyceryletherphosphorylcholine. Plateletactivating factor paf, 10alkyl2acetylsn glycero3phosphocholine is a potent biological mediator that exerts its effects in a variety of cells and. Slideshare uses cookies to improve functionality and performance, and to provide you with relevant advertising. The distinguishing property of pafahs is their unique substrate specificity they act on the phospholipid. Rupatadine ur12592, 8chloro6,11dihydro1115methyl3pyridinylmethyl4piperidinylidene5 h benzo5,6cyclohepta1,2bpyridine is a novel compound that inhibits both platelet activating factor paf and histamine h1 effects through its interaction with specific receptors k i app values against 3hweb2086 binding to rabbit platelet membranes and 3hpyrilamine binding to. Plateletactivating factor is a ubiquitous and potent lipid inflammatory mediator 12. Platelet activating factor binds to a unique gprotein coupled seven transmembrane receptor and triggers multiple intracellular signaling pathways. Plateletactivating factor paf is a mediator of inflammation that is implicated in cvd and hiv1 infection, shares mechanisms of immune activation with oxidized lipoproteins, and its receptor pafr is also found on tcells and macrophages.
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. All structured data from the file and property namespaces is available under the creative commons cc0 license. Platelet activating factor paf is a lipid mediator involved in several allergic reactions. 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. Plateletactivating factor paf is a phospholipid with potent, diverse physiological actions, particularly as a mediator of inflammation. Informations about elisa kit for platelet activating factor receptor pafr sec753hu5. However, we found that the paf made by endothelial cells is. Plateletactivating factor an overview sciencedirect.
Plateletactivating factor paf is a lipid mediator involved in several allergic reactions. Paf is not stored but is rapidly generated via enzymatic acetylation of the precursor 1 o hexadecyl2hydroxy sn glycero3phosphocholine lysopaf. Later observations by siraganuan and osler observed the existence of a diluted substance that had the capacity to cause platelet activation. Opposing effects of plateletactivating factor and lyso. Platelet activating factor is a potent biological mediator that exerts its effects in a variety of cells and tissues.
Nephrol dial transplant urinary excretion of plateletactivating factor in human and experimental nephrosis c. Many of the actions of paf can be mimicked by structurally related phospholipids that are. It is also involved in changes to vascular permeability, the oxidative burst, chemotaxis of leukocytes, as well as augmentation of. Plateletactivating factor paf is a proinflammatory lipid mediator possessing a unique 1oalkyl glycerophospholipid gpc backbone. At first, results of organic compounds natural and synthetic ones and specific and nonspecific as inhibitors of paf are reported. Follicle rupture during ovulation is associated with inflammationlike changes. Plateletactivating factor and related lipid mediators. Coagulation factors, phosphatidylserine, platelet receptors, thrombin summary platelet activation and blood coagulation are complementary, mutually dependent processes in haemostasis and thrombosis. Plateletactivating factor and the release of a platelet. The involvement of platelet activating factor in ovulation. Files are available under licenses specified on their description page. The ginkgolide, a unique c 20 cage molecule, is a naturally occurring plateletactivating factor paf antagonist braquet 1987.
If a firm is not confident in its ability to collect on its credit sales, it may sell the right to receive payment to the factor at a discount. Platelet activating factor paf at 100nm induced a biphasic calcium response in microglia culture. Plateletactivating factor receptors mediate excitatory. It has a role as a betaadrenergic antagonist, an antihypertensive agent, a bronchoconstrictor agent. Streptococcus pneumoniae anchor to activated human cells by the receptor for platelet activating factor. Platelets interact with several coagulation factors, while the coagulation product thrombin is a potent platelet activating agonist.
Because platelet activating factor paf participates in the inflammatory process, the effect of a pafspecific antagonist, bn52021, on the ovulatory response was tested in rats. Plateletactivating factor acetylhydrolases pafahs, ec 3. Gray matter degeneration contributes to progressive disability in multiple sclerosis ms and can occur out of proportion to measures of white matter disease. Factor a third party that buys a firms accounts receivable. Plateletactivating factor is a potent inflammatory mediator. Subodh kumar senior scientist,senior scientist, division of animal geneticsdivision of animal genetics indian veterinary research institute, izatnagarindian veterinary research institute, izatnagar 2. In 1972, the term platelet activating factor paf was coined by benveniste, henson, and cochrane. Streptococcus pneumoniae anchor to activated human cells. Paf is considered a potential relevant mediator in allergic rhinitis, with a key. Plateletactivating factor and related lipid mediators springerlink. Variation in plasma plateletactivating factor degradation. The factor then assumes the credit risk associated. Plateletactivating factor paf is a potent inflammatory mediator that mimics many of the features of asthma, including eosinophil recruitment and activation and.
Emphasis is given on recent results about a new class of the socalled metalbased inhibitors of paf. 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. Platelet activating factor is a biologically potent phospholipid that may mediate cell damage in patients with myocardial ischemia. Paf is a potent mediator of anaphylaxis and inflammation and is also implicated in shock, graft rejection, renal diseases. In plasma, its inactivation to lyso platelet activating factor is catalyzed by a specific, lipoproteinassociated acetylhydrolase. Plateletactivating factor paf in allergic rhinitis. Plateletactivating factor is identified as 1oalkyl2acetylsnglycero3phosphocholine 12.
Due to its role, it has been also considered as a hormone or a primitiveuniversal cellular biological regulator 12. Pdf plateletactivating factor paf is a phospholipid with potent, diverse physiological actions, particularly as a mediator of inflammation. Factor a financial institution that buys a firms accounts receivable and collects the accounts. It is released from multiple cells of the immune system, such as eosinophils, neutrophils, and mast cells, and also exerts its effect on most of them upon specific binding to its receptor, becoming a pleiotropic mediator. To further examine this response, we performed detailed studies of cardiovascular function after paf administration. Plateletactivating factor paf is a phospholipid that was discovered as a platelet agglutinating factor derived from rabbit basophils and as a depressor substance derived from the renal medulla. Rupatadine, a new potent, orally active dual antagonist of.
Kay department ofallergyandclinicalimmunology, cardiothoracicinstitute, bromptonhospital, london, sw36hp, unitedkingdom abstract plateletactivating factor pafacether, an inflammatory me diator with a wide range ofbiological activities. Plateletactivating factor pafantagonists of natural. The structure and function of plateletactivating factor. Role of plateletactivating factor paf in the initiation. Plateletactivating factor the journal of lipid research. Paf is a unique and novel signalling phospholipid that has pleiotrophic biological properties in addition to platelet activation and is produced by a variety of cell types snyder, 1987. Plateletactivating factor paf definition of platelet.
Paf is formed by a smaller number of cell types than the eicosanoids, mainly leukocytes, platelets, and endothelial cells. Pdf plateletactivating factor and related lipid mediators. Because lipoprotein levels decrease after myocardial infarction, a possible reduction was suspected to occur in plasma. Bn52021, administered locally, inhibited follicle rupture in rats stimulated to ovulate with human chorionic gonadotropin hcg. 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. Sudden release of platelet activating factor paf into the circulation can cause hypotension, tachycardia, and circulatory collapse.
Abstract plateletactivating factor paf is a phospholipid with potent, diverse physiological actions, particularly as a mediator of inflammation. Elisa kit for platelet activating factor receptor pafr. Plateletactivating factor paf financial definition of. Paf is a phospholipid 10alkyl2acetylsnglycero3phosphorylcholine that has been implicated as a mediator in diverse pathologic processes. Jcm free fulltext plateletactivating factor paf in.
Although white matter pathology, including demyelination and axon injury, can lead to secondary gray matter changes, we hypothesized that neurons can undergo direct excitatory injury within the gray matter independent of these. Paf is a potent phospholipid activator and mediator of many leukocyte functions, including platelet aggregation, inflammation, and anaphylaxis. Plateletactivating factor and related lipid mediators annual. Pdf enzymatic pathways for plateletactivating factor, related alkyl. Pafr is linked to multiple intracellular signaling pathways, including the p38 mapk and pi 3k pathways, through increasing. The structure of paf was later elucidated by demopoulos, pinckard, and hanahan in 1979.