【摘要】 目的了解甘氨酰谷氨酰胺二肽（简称甘谷二肽）对严重烧伤大鼠心肌力学功能的保护作用,并探讨其机制。方法将136只Wistar大鼠分成对照组8只（不予烧伤）、烧伤组32只、谷氨酰胺组32只、甘氨酸组32只、甘谷二肽组32只。后4组均造成30%TBSAⅢ度烧伤。5组大鼠依次给予酪氨酸1.5g·kg^-1·d^-1、酪氨酸1.5 g·kg^-1·d^-1、谷氨酰胺1.0 g·kg^-1·d^-1+酪氨酸0.5 g·kg^-1·d^-1、甘氨酸0.5 g·kg^-1·d^-1+酪氨酸1.0g·kg^-1·d^-1、甘谷二肽1.5 g·kg^-1·d^-1。伤后12、24、48、72 h检测大鼠心肌组织还原型谷胱甘肽（GSH）、腺苷一磷酸（AMP）、腺苷二磷酸（ADP）、腺苷三磷酸（ATP）、细胞能荷（EC）的含量和主动脉收缩压（AOSP）、主动脉舒张压（AODP）及左心室收缩压（LVSP）、左心室压力变化最大上升速率（+dp/dtmax）。结果后4组大鼠伤后心肌组织GSH、ATP和EC含量以及AOSP、AODP、LVSP、+dp/dtmax检测值普遍低于对照组（P<0.01）,AMP、ADP含量则普遍高于对照组（P<0.01）。与烧伤组比较,后3组上述指标均有明显改变。伤后12h甘谷二肽组的GSH含量为（72.7±1.7）μmol/g,高于谷氨酰胺组（67.8±3.8）μmol/g（P<0.01）;该时相点EC、AOSP的检测值亦高于谷氨酰胺组（P<0.01）。伤后48 h甘谷二肽组GSH、EC、AOSP的检测值高于甘氨酸组（P<0.01）。结论大鼠烧伤后给予谷氨酰胺、甘氨酸和甘谷二肽,能不同程度改善心肌组织GSH、高能磷酸化合物含量,缓解心肌力学功能的下降。甘谷二肽的疗效明显优于谷氨酰胺或甘氨酸,提示它对烧伤后心脏功能的保护作用具有协同效应。更多还原

【Abstract】 Objective To investigate the protective effects of glycyl-glutamine dipeptide supplement on the function of myocardial dynamics in severely burned rats,and to explore its mechanism.Methods One hundred and thirty-six Wistar rats were randomly divided into five groups:i.e,control group（C,n= 8,without burns）,burn group（B,n=32）,Gin group（Gin,n=32）,Gly group（Gly,n=32）and Gly-Gln group（Gly-Gln,n=32）.The rats in the latter four groups were respectively treated with tyrosine(1.5 g·kg^-1·d^-1),glutamine(1.0 g·kg^-1·d^-1)and tyrosine(0.5 g·kg^-1·d^-1),glycine(0.5 g·kg^-1·d^-1)and tyrosine(1.0 g·kg^-1·d^-1),and Glycyl-glutamine dipeptide(1.5 g·kg^-1·d^-1)after receiv- ing a 30% TBSA full-thickness burn on the back.Glutathion（GSH）,adenosine monophosphate（AMP）,a- denosine diphosphate（ADP）,adenosine triphosphate（ATP）,cell energy charge（EC）and the index of myo- cardial dynamics（ASOP,AODP,LVSP,+dp/dtmax）were measured atl2,24,48,72 post-burn hours （PBH）.Results The content of GSH,ATP,EC and the level of aortic systolic pressure（ASOP）,aortic diastolic blood pressure（AODP）,left ventricular end diastolic pressure（LVEDP）and maximum rate of intra- ventricular pressure rise/down（+dp/dtmax）in B,Gin,Gly,Gly-Gln groups were obviously lower than those in C group（P<0.01）,while the levels of AMP and ADP showed an opposite tendency.Compared with B group,the above indices were ameliorated.The content of GSH（72.7±1.7）μmol/g in Gly-Gln group at 12 PBH was obviously higher than that in Gln group（67.8±3.8）μmol/g（P<0.01）.The levels of EC and AOSP were obviously higher in Gly-Gln group than that in Gin group（P<0.01）.The level of GSH,EC,AOSP in Gly-Gln groups were obviously higher than those in Gly group at 48 PBH.Conclusion Glycyl-glutamine dipeptide,Gly and Gin supplementation after burns can improve the content of GSH and high energy phosphate compound,and suppress the decline of myocardial dynamics function.The effects of Glycyl-glutamine dipeptide is better than single Gly or Gln,indicating that the protective effect on myocardi- al function after severe burns by Gin and Gly is synergistic.更多还原