Lv Shang-jun, Zhang Yong, Sun Yong, Wu Wei, You Zhong-yi, Wang Shi-liang, Peng Xi
Institute of Burn Research, Southwest Hospital, State Key Laboratory of Trauma, Burns and Combined Injury, the Third Military Medical University, Chongqing, P. R. China.
Zhonghua Shao Shang Za Zhi. 2007 Aug;23(4):244-8.
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.
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), Gln group (Gln, 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 x kg(-1) x d(-1)), glutamine (1.0 g x kg(-1) x d(-1)) and tyrosine (0.5 g x kg(-1) x d(-1)), glycine (0.5 g x kg(-1) x d(-1)) and tyrosine (1.0 g x kg(-1) x d(-1)), and Glycyl-glutamine dipeptide (1.5 g x kg(-1) x d(-1)) after receiving a 30% TBSA full-thickness burn on the back. Glutathione (GSH), adenosine monophosphate (AMP), adenosine diphosphate (ADP), adenosine triphosphate (ATP), cell energy charge (EC) and the index of myocardial dynamics (ASOP, AODP, LVSP, + dp/dtmax) were measured at 12, 24, 48, 72 post-burn hours (PBH).
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 intraventricular pressure rise/down (+ dp/dtmax) in B, Gln, 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) micromol/g in Gly-Gln group at 12 PBH was obviously higher than that in Gln group (67.8 +/- 3.8) micromol/g (P < 0.01). The levels of EC and AOSP were obviously higher in Gly-Gln group than that in Gln 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.
Glycyl-glutamine dipeptide, Gly and Gln 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 myocardial function after severe burns by Gln and Gly is synergistic.
探讨补充甘氨酰谷氨酰胺二肽对严重烧伤大鼠心肌动力学功能的保护作用及其机制。
将136只Wistar大鼠随机分为5组，即对照组（C组，n = 8，未烧伤）、烧伤组（B组，n = 32）、谷氨酰胺组（Gln组，n = 32）、甘氨酸组（Gly组，n = 32）和甘氨酰谷氨酰胺组（Gly-Gln组，n = 32）。后4组大鼠背部给予30%体表面积的全层烧伤后，分别给予酪氨酸（1.5 g·kg⁻¹·d⁻¹）、谷氨酰胺（1.0 g·kg⁻¹·d⁻¹）和酪氨酸（0.5 g·kg⁻¹·d⁻¹）、甘氨酸（0.5 g·kg⁻¹·d⁻¹）和酪氨酸（1.0 g·kg⁻¹·d⁻¹）、甘氨酰谷氨酰胺二肽（1.5 g·kg⁻¹·d⁻¹）。于烧伤后12、24、48、72小时（PBH）测定谷胱甘肽（GSH）、一磷酸腺苷（AMP）、二磷酸腺苷（ADP）、三磷酸腺苷（ATP）、细胞能荷（EC）及心肌动力学指标（主动脉收缩压（ASOP）、主动脉舒张压（AODP）、左心室收缩压（LVSP）、室内压最大上升/下降速率（+ dp/dtmax））。
B组、Gln组、Gly组、Gly-Gln组的GSH、ATP、EC含量及主动脉收缩压（ASOP）、主动脉舒张压（AODP）、左心室舒张末期压（LVEDP）和室内压最大上升/下降速率（+ dp/dtmax）水平均明显低于C组（P < 0.01），而AMP和ADP水平呈相反趋势。与B组相比，上述指标有所改善。烧伤后12小时Gly-Gln组的GSH含量（72.7±1.7）μmol/g明显高于Gln组（67.8±3.8）μmol/g（P < 0.01）。Gly-Gln组的EC和AOSP水平明显高于Gln组（P < 0.01）。烧伤后48小时Gly-Gln组的GSH、EC、AOSP水平明显高于Gly组。
烧伤后补充甘氨酰谷氨酰胺二肽、甘氨酸和谷氨酰胺可提高GSH和高能磷酸化合物含量，抑制心肌动力学功能下降。甘氨酰谷氨酰胺二肽的效果优于单一的甘氨酸或谷氨酰胺，表明谷氨酰胺和甘氨酸对严重烧伤后心肌功能的保护作用具有协同性。
