银杏叶提取物对1型糖尿病大鼠左心室收缩功能的影响

Effect of Ginkgo biloba extract on left ventricular systolic function in type I diabetic rats

目的探讨银杏叶提取物(EGB)对1型糖尿病大鼠左心室收缩功能的影响。方法 30只雄性SD大鼠随机分为正常对照组(CON组)、糖尿病模型组(DM组)和银杏叶提取物干预组(EGB组),每组10只。其中后两组用腹腔注射链脲佐菌素(STZ)以诱导1型糖尿病模型。制模成功后,EGB组腹腔注射EGB溶液[8mg/(kg·d)],另两组注射等量0.9%氯化钠注射液。12周后所有大鼠行常规超声心动图及速度向量成像(VVI)检查,测定左心室射血分数(LVEF)、左心室短轴缩短率(LVFS)、乳头肌水平左心室壁各节段收缩期平均峰值速度(Vs)、径向应变(Sr)及径向应变率(SRr),行心导管检查,测定左心室收缩末压力(LVESP)、左心室舒张末压力(LVEDP)及左心室内压最大上升/下降速率(LV±dp/dt_(max))。处死大鼠后取出心肌组织,分别通过天狼星红染色、TUNEL凋亡染色测定各组大鼠心肌胶原容积分数(CVF)及心肌凋亡指数(AI)。结果 EGB干预12周后,DM组大鼠LVEF、LVFS、Vs、Sr、SRr、LVESP、+dp/dtmax及-dp/dtmax明显均低于正常对照组(均P<0.05),LVEDP、CVF及AI测定值均明显高于正常对照组(均P<0.05),EGB组LVEF、LVFS、Vs、Sr、SRr、LVESP、+dp/dt_(max)及-dp/dt_(max)较DM组均明显增高(均P<0.05);LVEDP、CVF及AI测定值均明显减低(均P<0.05)。结论 EGB通过减少心肌细胞凋亡,减轻心肌间质纤维化,从而有效改善DM大鼠左心室收缩功能。

Objective To investigate the effect of Ginkgo biloba extract(EGB)on left ventricular systolic function in type I diabetic rats.Methods Thirty male Sprague-Dauley rats were randomly divided into three groups:normal control group(control group,n=10)DM model group(DM group,n=10)and EGB-treated group(EGB group,n=10).Type I diabetes was induced by intraperitoneal injection of streptozotocin in animals of DM and EGB groups.EGB was given by intraperitoneal injection in EGB group and normal saline was injected to the rats of other two groups.Twelve weeks later all rats underwent conventional echocardiography and velocity vector imaging(VVI)exams.Left ventricular ejection fraction(LVEF)and left ventricular fractional shortening(LVFS)were measured with echocardiography.The segmental mean peak systolic radial velocity(Vs)systolic radial strain(Sr)and systolic radial strain rate(SRr)of six walls at the papillary muscle level were measured in left ventricular short-axis view by VVI.Then all the rats underwent the cardiac catheter exam to obtain the left ventricular end-systolic pressure(LVESP)left ventricular end-diastolic pressure(LVEDP)and the maximal increase/decrease rate of left ventricular pressure(LV±dp/dtmax).The myocardial tissue samples were stained with Sirius red staining to quantify the myocardial collagen volume fraction(CVF)and the myocardial tissue apoptosis index(AI)was determined with TUNEL method.Results Twelve weeks after intervention the LVEF,LVFS,Vs,Sr,SRr,LVESP,+dp/dtmax and-dp/dtmax in the DM group were significantly lower than those in the control group(P<0.05)and the LVEDP,CVF and AI in the DM group were significantly higher than those in the control group(P<0.05).Compared to the DM group,the LVEF,LVFS,Vs,Sr,SRr,LVESP,+dp/dtmax and-dp/dtmax in the EGB group were significantly increased(P<0.05)and the LVEDP,CVF and AI significantly decreased(P<0.05).Conclusion EGB can effectively improve the left ventricular systolic dysfunction in diabetic rats by reducing cardiomyocyte apoptosis and alleviating myocardial interstitial fibrosis.