资源描述：
《NATURAL ANTICOAGULANTS, AGING,》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、ExperimentalGerontology,Vol.33,Nos.7/8,pp.891±896,1998Copyright©1998ElsevierScienceInc.PrintedintheUSA.Allrightsreserved0531-5565/98$19.001.00PIIS0531-5565(98)00047-3NATURALANTICOAGULANTS,AGING,ANDTHROMBOEMBOLISMANDREASAGRIPANTIandANGELOCARPIDipartimentidiMedicinaInternaediMedicinadel
2、laProcreazioneedell'EtaÁEvolutiva,UniversitaÁdegliStudidiPisa,ItalyAbstractÐThenormalagingprocessaltersbloodcoagulationsysteminhumans;thismaybeofgreatconcernintheviewoftheknownassociationofvasculardiseasewithadvancingage.Theplasmaconcentrationofseveralcoagulationfactors,namelyfibrinog
3、en,factorVII,factorVIII,factorIX,highmolecular-weightkininogen,andprekallikrein,increaseinhealthyhumans,parallelingthephysiologicalagingprocess.Plasmaparametersofclottingactivationinvivo,suchasprothrombinfragment112,fibrinopeptideA,thrombin±antithrombinIIIcomplex,andD-dimer,arepositiv
4、elycorrelatedwithage.Nevertheless,amongcentenarians,biochemicalsignsofmarkedhypercoagulabilityareassociatedwithahealthystate.Naturalanticoagulants,includingantithrombinIII,heparincofactorII,proteinC,proteinS,andtissuefactorpathwayinhibitor,canmodulatethereactionsofbloodcoagulationsyst
5、em.TheoccurrenceofmenopauseisaccompaniedbyasignificantincreaseinantithrombinIIIplasmalevel;themeanantithrombinIIIlevelsinolderwomenexceedlevelsinmalecontemporaries.InhealthyelderlysubjectsheparincofactorIIplasmaconcentrationsarelowerthaninyoungsubjects,independentlyofgender.ProteinCle
6、velsraisewithageinbothsexes,aswellasfreeproteinSlevels.Inwomen,statisticallysignificantincreasesintheplasmaconcentrationofthetissuefactorpathwayinhibitorhavebeenobserved,whereasnosignificantage-relatedchangehasbeenfoundinmen.Thefactthatmanysubjectswithcongenitaldefectsofnaturalanticoa
7、gulantsdonotundergothromboemboliceventsinyoungagesuggeststhatinhealthyindividualsaraiseinnaturalanticoagulantscanbalancetheage-relatedincreaseofproco-agulantfactors.©1998ElsevierScienceInc.KeyWords:naturalanticoagulants,aging,thromboembolismINTRODUCTIONTHEPHYSIOLOGICALAGINGprocessresu
8、ltsin
