简介：Objective:ToinvestigateCaspase-3expressionanditsroleinneuronalapoptosis.Methods:TheT13-L2spinalcordofratswasinjuredbytractionaftertheamplitudeofP1-N1wave,monitoredbyacorticalsomatosensoryevokedpotential(CSEP)monitor,decreasedtoseventypercentofthatbeforeoperation.Thenratswerekilledin6h,1d,4d,7d,14dand21drespectivelyafteroperation.Flowcytometerterminaldeoxynucleotldyltransferease-mediatedbiotinylateddeoxynuridinetriphosphatenickendlabeling(TUNEL),Caspase-3activityassayandimmunohistochemicalmethodwereappliedtoinvestigateCaspase-3expressioninthespinalcordtissueandtostudyneuronalapoptosisinrats.Results:Afterspinalcordinjury,apoptoticcellsdetectedbyflowcytometryandTUNEL-positivecellsweresignificantlymore,andpositiveimmunohistochemicalstainingofCaspase-3andCaspase-3activityweresignificantlyhigherinGroupinjurythaninGroupscontrolandlaminectomy,respectively(P>0.05,P>0.01).Similartrendofchangeswasnoticedinapoptoticcells,TUNEL-positivecellsandpositiveimmunohistochemicalstainingofCaspase-3,allofwhichreachedtheirrespectivepeak7daysafteroperation.Caspase-3activityreacheditspeak,however,4dayspostoperatively.Conclusions:IncreasedexpressionandactivityofCaspase-3proteininneuronsaftertractivespinalcordinjuryisthebiochemicalsignalofearlyspinalcellapoptosis.Itisofgreatsignificanceforunderstandingthemechanismofspinalcordinjury.