ghrelin对大鼠血压和心肌收缩功能的影响

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1、第四军医大学硕士学位论文大鼠血流动力学的影响；；2.以成年SD大鼠的心肌细胞为观察对象，采用单细胞动态边缘检测系统测定细胞收缩功能的变化；3.以离体大鼠腹主动脉条为观察对象，采用离体血管灌流，观察ghrelin对离体大鼠腹主动脉的作用；获得的主要结果如下：1．Ghrelin（1×10-7~1×10-4g/kg）可剂量依赖性降低大鼠平均动脉压，对左室内压有一定影响，而对大鼠心率等心血管动力学指标无影响。2．Ghrelin（1×10-6mol/L）可剂量依赖性降低单个心肌细胞收-9~1×10缩最大收缩幅度、最大缩短和

2、复长速率。3.Ghrelin（1×10-6mol/L）可舒张离体鼠腹主动脉。以上结果提示：1.Ghrelin具有负性肌力作用。2.Ghrelin对动脉有显著的舒张作用，对心脏的负性调节作用及对动脉血管的舒张作用是其降压作用的主要原因。综上所述，本研究证实了ghrelin具有明显的负性肌力作用和心脏抑制作用，同时发现其可舒张腹主动脉。关键词：Ghrelin；血管舒张；离体血管灌流；平均动脉血压；左室内压；心肌收缩-3-第四军医大学硕士学位论文Effectofghrelinonbloodpressureofratsa

3、ndcontractilefunctionofcaodiomyocytesCandidateformaster:CaoYukunSupervisor:YuShiqiangDepartmentofcardiovascularsurgery,xijinghospital,FourthMilitaryMedicalUniversity,Xi’an710032,ChinaAbstractGhrelin,secretedfromthestomach,stimulatesthereleaseofgrowthhormone.G

4、hrelinbindstogrowthhormonesecretagogue–receptor(GHSR),clonedfromthemammalianpituitarygland.FurtherstudiesrevealedwidespreadexpressionofGHSRinperipheraltissuessuchascardiovascularsystem,indicatingthatitmighthavemultiplephysiologicaleffects.Therearestillsomedis

5、putesoveritseffectsoncardiovascularsystem.ThoughtheresearchofghrelinlevelinhealthyobeseandleanmenandwithMRItoanalyzethestructureandfunctionofheart,NicholasfoundthatghrelinhadnegativeeffectonRVESVandpositiveeffectonRVEF.Subcutaneousadministrationofghrelincanin

6、creasecardiaccontractility,LVEFandvolumeejection,decreaseLVESV.Ontheotherside,ghrelinmayhavedirecteffectonmyocardium.SubcutaneousadministrationofghrelintoratscanincreaseLVEFofdilatedcardiomyopathyandgrowthhormonedeficientrat.Recentresearchsuggestedthatghrelin

7、decreasecontractilefunctionofratpapillarymusclesinaconcentration-dependentmanner.Inrecent-4-第四军医大学硕士学位论文years,theregulatefunctionofghrelinespeciallytocardiovascularsystemhasattractgreatconcerns,andsuggeststhatitmayhavepontentialremedyeffecttocardiovasculardis

8、eases.Ourstudyfocusedontheeffectsofghrelinonthecardiovascularsystemanditsprobablemechanism,andtriedtodiscussthepotentialclinicalvalueofghrelinincuringthecardiovasculardiseases.Themaincont