SpantidepreventsupregulationofnitricoxidesynthaseexpressionandnitricoxideproductioninthespinalcordinducedbyfomaldehydeinratsLIWenBin,SUNXiaoCai,LIQingJun,LIShuQin,CHENXiaoLing(DepartmentofPathophysiology,InstituteofBasicMedicine,HebeiMedicalUniversity,Shijiazhuang050017,China)Abstract:AIMTostudytheeffectofspantide{[DArg1,DTrp7,9,Leu11]substanceP},anantagonistofsubstanceP(SP),ontheupregulationofnitricoxidesynthase(NOS)andnitricoxide(NO)inthespinalcordofratduringinflammatorypainandhyperalgesia.METHODSTheinflammatorypainandhyperalgesiawereinducedbysubcutaneousinjectionof5%fomaldehyde0.2mLintotherighthindpawoftherats.NOSexpressionlevelwasdeterminedusingNADPHdiaphorasehistochemistry,andNOproductionwasdeterminedbynitratereductasemethod.RESULTSThefomaldehydeinjectionsignificantlyincreasedNOSexpressionlevelandNOproductioninthedorsalhornoftheL5segmentofthespinalcordfollowingpainandhyperalgesia.Theincreasesreacheditspeak24haftertheinjection.Intrathecalinjectionofspantide(5μg,10μL)5minpriortothefomaldehydeinjectionsubstantiallyinhibitedtheincreasesinNOSexpressionandNOproduction.CONCLUSIONThereleaseofSPresultedfromnociceptiveafferentsplaysanimportantroleintheincreasesinNOSexpressionandNOproductioninthespinalcordofratwithpainandhyperalgesiainducedbythefomaldehydeinjection.Keywords:pain;hyperalgesia;substanceP;spantide;nitricoxidesynthase;nitricoxide;spinalcordCLCnumber:R963Documentcode:AArticleID:10003002(2004)04024107Nitricoxide(NO)hasbeenshowedtobeanovelandimportantneurotransmitterinthecentralnervoussystem[1].ManyexperimentalstudiesReceiveddate:20031118Accepteddate:20040326Foundationitem:TheprojectsupportedbyagrantfromDepart...