炎症的化学介质课件.ppt

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1、ChemicalMediatorsofInflammationLeukocyteactivation.Differentclassesofcellsurfacereceptorsofleukocytesrecognizedifferentstimuli.Thereceptorsinitiateresponsesthatmediatethefunctionsoftheleukocytes.Onlysomereceptorsaredepicted.ClickforMovieNECROSIS:AwhitebloodcelldiesafteramealI

2、ngesting“leukotoxic”StreptococcuspyogenesReactionsaresimilarirrespectiveoftissueortypeofinjury2.Reactionsoccurinabsenceofnervousconnections“Chemicalsubstancesmediateallphasesofacuteinflammation”Thomas,Lewis(1913-1993)Chemicalmediatorsofinflammation(EC:endothelialcells)Vasodil

3、atation:HistamineProstaglandinsNitricoxideIncreasedvascularpermeability:HistamineAnaphylatoxinsC3aandC5aKininsLeukotrienesC,D,andEPAFSubstancePChemotaxis:ComplementfragmentC5aLipoxygenaseproducts,lipoxins&leukotrines(LTB4)ChemokinesTissueDamageLysosomalproductsOxygen-derivedr

4、adicalsNitricOxydeEventsinAcuteInflammationProstaglandins:VasodilationPainFeverPotentiatingedemaIL-1andTNF:Endothelial-leukocyteinteractionsLeukocyterecruitmentProductionofacute-phasereactantsDiversityofEffectsofChemicalMediatorsVASODILATATIONBasophils&MastCellsHistamineAdipo

5、setissueshowingmastcellsaroundbloodvesselsandintheinterstitialspace.Stainedwithmetachromaticstaintoidentifythemastcellgranules(darkblueorpurple).Theredstructuresarefatglobulesstainedwithfatstain(oilred)MastCells&AllergyUltrastructureandcontentsofneutrophilgranules,stainedforp

6、eroxidaseactivity.Thelargeperoxidase-containinggranulesaretheazurophilgranules;thesmallerperoxidase-negativeonesarethespecificgranules(SG).N,portionofnucleus.LEUKOTRINES&PROSTAGLANDINSLeukotrienesandProstaglandins:PotentmediatorsofinflammationDerivedfromArachidonicacid(AA):20

7、-carbon,unsaturatedfattyacidproducedfrommembranephospholipids.Principalpathways:5-lipoxygenase:Producesacollectionofleukotrienes(LT)Cyclooxygenase(COX):ProducesprostaglandinH2(PGH2)PGH2servesassubstratefortwoenzymaticpathways:Prostaglandins(PG)Thromboxanes(Tx).Biosynthesisofl

8、eukotrienesandlipoxinsbycell-cellinteraction.AA:arachidonicacid–deri