简介：BACKGROUND:Ithasbeensuggestedthatmelatonin(MT)canprotectsecondaryneuronalinjury.However,theprotectiveeffectofMTonneuronalinjuryinischemia/reperfusionmodelsinvitrostillhasnotbeenproved.OBJECTIVE:ToinvestigatetheprotectiveeffectofMToncentralischemicinjuryofnervecellsandanalyzeitspossiblemechanism.DESIGN:Contrastobservationalstudy.SETTING:DepartmentofBiochemistryandMolecularBiology,TongjiMedicalCollege,HuazhongUniversityofScienceandTechnology.MATERIALS:Ratsaged7-8daysandweighing10-12gwereprovidedbyMedicalExperimentalAnimalCenter,TongjiMedicalCollege,HuazhongUniversityofScienceandTechnology,MTwasprovidedbySigmaCompany,USA.METHODS:TheexperimentwascarriedoutintheLaboratoryofBiochemistryandMolecularBiology,TongjiHospital,HuazhongUniversityofScienceandTechnologyfromOctober2002toMarch2004.TheeffectsofMTontheneurodegenerationinducedbyoxygen-glucose-deprivation(OGD)weretestedinculturedratcerebellargranulecells.NeurondamagewasquantitativelyassessedbyTypanBlueexclusionandMTTassayatdifferenttimepointsafteroxygen-glucose-deprivation(90minutes).DNAgelelectrophoresisandacridineorangestainwereperformedtodeterminethenatureofcelldamage.Andfluorescencespectrophotometerwasusedforquantificationofintracellularmalondialdehyde(MDA)atvarioustimeintervals.MAINOUTCOMEMEASURES:Correlationbetweendegreesofneuronalinjuryandreperfusiontimes,apoptosis,andproductionofMDAincells.RESULTS:①Theneuroninjurywasaggravatedwithreperfusiontime.②TheprotectiveeffectofMTwastime-anddose-dependentwhenitsconcentrationwasnothigherthan10μmol/L.⑧WhenneuronswereexposedtoOGDfor90minutes.partofthecellsexhibitedtypicalfeaturesofapoptosis:internucleosomalDNAcondensationandDNAladderonagarosegelelectrophoresis.MTaddedtocellsrecoveringfromOGDexertedneuroprotectiveactionagainstOGD-inducedapoptosis.④InOGDexposedculture