考察用靜息張力表征離體蟾蜍腓腸肌等長收縮能力的有效性。方法 SOD抑制劑和維生素C聯合作用蟾蜍腓腸肌，記錄電刺激（12VDC，2ms波寬，2s間隔）下等長收縮張力變化，單指數函式加權擬合90%峰張力後的鬆弛過程測定鬆弛速度和靜息張力表徵收縮能力。結果 收縮1.0min後對照靜息張力在7.0min內單調下降而藥物處理後靜息張力先降後升，7.0min後處理組靜息張力相對初始值的增加值顯著高於對照組。同時，對照鬆弛速度大多單調下降，藥物處理後鬆弛速度多數先升後降，且10.0min內其鬆弛速度總低於相同時刻的對照組。結論 靜息張力可反映肌肉收縮能力。
ObjectiveTocharacterizetheisometriccontractilityofBufogastrocnemiusexvivoinlightoftheresttension.MethodsBufogastrocnemiustreatedwithSODinhibitorandascorbatewasstimulatedelectrically(12VDC,2msdurationwitha2sinterval)torecordthetensionwithin10min.Weightedfittingtotherelaxationcurveofthetensionbelow90%ofthepeaktensionwithamono-exponentialmodelyieldedtheresttensionandrelaxationrate.ResultsThecontrolgastrocnemiusshowedmonotonicdecreaseoftheresttension,buttreatmentwithSODinhibitorandascorbateresultedinadecreaseoftheresttensionfollowedbyafastincreasewithina1.0mincontraction.Theincreaseoftheresttensionat7.0minofcontractionofthetreatedmusclewassignificantlygreaterthanthatofthecontrolmuscle.Thecontrolmuscleshowedamonotonicdecreaseoftherelaxationratein10min,whereastreatmentwithSODinhibitorandascorbateproducedincreasedrelaxationratefollowedbymonotonicdecreasetillaplateauwasreached.Inthecourseofthe10minrecording,therelaxationrateofthetreatedmusclewaslowerthanthatofthecontrolafterthesamedurationofcontraction.ConclusionResttensionisacharacteristicindextorepresenttheskeletalmusclecontractility.
關鍵字蟾蜍腓腸肌,等長收縮能力,肌肉損傷,靜息張力,鬆弛速度;Bufogastrocnemius,isometriccontractility,muscledamage,resttension,relaxationrate
