摘要目的 观察西洋参叶20s-原人参三醇组皂苷(PQTS)对压力超负荷性大鼠心室重构的保护作用.方法 Wistar大鼠随机分为假手术组、模型组、阳性药卡托普利组及PQTS低、中、高剂量组.结扎大鼠腹主动脉建立压力超负荷性心室重构模型,PQTS按12.5、25.0、50.0mg·kg-1·d-1连续腹腔注射6周,检测心室脏器系数、心肌组织病理学及血流动力学参数,测定血清丙二醛( MDA)含量及超氧物歧化酶(SOD)活性,血浆前列环素(PGI2)、血栓素A2 (TXA2)、内皮素(ET)及血管紧张素Ⅱ(AngⅡ)含量.结果 与重构模型组比较,PQTS能明显抑制心室重构大鼠心肌组织的病理性改变,降低心室质量及心脏系数,明显升高收缩压、舒张压、平均动脉压、左室收缩压及左心室内压最大上升和下降速率(±dp/dtmax),降低心率及左室舒张末压,可明显降低血清MDA含量,升高SOD活性,亦能明显降低血浆ET、AngⅡ及TXA2含量,提高PGI2含量及PGI2/TXA2比值(P＜0.05或P＜0.01).结论 PQTS对大鼠心室重构具有明显保护作用,可能与其改善心室重构大鼠的左心收缩和舒张功能,增强抗氧化酶活性,减少自由基及缩血管活性物质对心肌的损伤,纠正PGI2/TXA2失衡等机制有关.

abstractsObjective To investigate the protective effects of panax quinquefolium 20s-protopanaxtriol saponins (PQTS) on ventricular remodeling in rats with pressure overloaded hypertrophic myocardium.Methods Wister rats were randomly divided into operation,model,positive captopril,and low,moderate,high PQTS groups.The model of pressure overload-induced ventricular remodeling was established through the method of rat's abdominal aorta deligation.After 6 weeks of PQTS treatment ( 12.5,25.0 and 50.0 mg · kg-1 · d-1,i.p),myocardial morphological and hemodynamic parameters were determined.The content of malondialdehyde (MDA) and activity of superoxide dismutase (SOD) in serum,and the concentrations of prostacycline (PGI2),thromboxane A2 (TXA2),endothelium (ET) and angiotensin Ⅱ ( Ang Ⅱ ) in plasma were also determined.Results Compared with remodeling group,PQTS could inhibit myocardial pathological changes,decrease significantly ventricular weight and cardiac coefficient,increase significantly systolic blood pressure,diastolic blood pressure,mean arterial pressure,left ventricular systolic pressure and the maximum left ventricular pressure rising and dropping rates(dp/dtmax),reduce the heart rate and left ventricular end-diastolic pressure in ventricular remodeling rats.PQTS could also decrease the content of MDA and enhance significantly activity of SOD in serum.In addition,PQTS could decline the contents of ET,Ang Ⅱ and TXA2 in plasma while increase significantly the content of PGI2 in plasma and PGI2/TXA2 ratio(P＜0.05 or P＜0.01).Conclusions PQTS has protective effects on ventricular remodeling through improving systolic and diastolic function in ventricular remodeling rats,increasing anti-oxidase activity,reducing the damage of free radicals and vasoactive substance on myocardium,and correcting disequilibrium of PGI2/TXA2 in ventricular remodeling rats.