西洋参叶二醇组皂苷抗大鼠心室重构的作用机制

目的：观察西洋参叶二醇组皂苷（PQDS）对抗大鼠心室重构的作用机制。方法：结扎大鼠腹主动脉建立压力超负荷性心室重构模型，将Wistar雄性大鼠随机分为假手术组、重构模型组、阳性药物组（贝那普利组）及PQDS低、高剂量组。PQDS按50、100 mg?kg^-1?d^-1给大鼠连续灌胃6周，假手术组及重构模型组灌胃生理盐水10 mL?kg^-1?d^-1，阳性药物组灌胃贝那普利10 mg?kg^-1?d^-1。给药6周后测定心肌形态学参数，血清丙二醛（MDA）水平及超氧化物歧化酶（SOD）活性，血浆前列环素（PGI₂）、血栓素A₂（TXA₂）、一氧化氮（NO）及血管紧张素Ⅱ（AngⅡ）水平以及血浆和心肌内皮素（ET）含量。结果：与重构模型组比较，PQDS 100 mg?kg^-1组大鼠的心室重量及心脏系数均明显降低（P<0.05），血清MDA含量降低（P<0.05），SOD活性升高（P<0.05），血浆AngⅡ及TXA₂含量下降，PGI₂含量及PGI₂/TXA₂比值增高（P<0.05或P<0.01），血浆和心肌ET含量降低（P<0.05或P<0.01），血浆NO水平则无明显变化（P>0.05）。PQDS 50、100 mg?kg^-1组之间各项指标差异无显著性。结论：PQDS对大鼠心室重构具有保护作用，可能与其增强抗氧化酶活性，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。

Mechanism of action of PQDS on anti-ventricular remodeling in rats

Objective To observe the mechanism of action of panax quinquefolium diolsaponins (PQDS) on anti-ventricular remodeling in rats. Methods The model of pressure-loading ventricular remodeling was established through the method of rat’s abdominal aorta deligation. The male Wistar rats were divided into 5 groups,including sham operation group,remodeling model group,Benazepril group,and low and high dose groups of PQDS. The rats were treated with PQDS (with dose of 50 and 100 mg·kg-1 i.g) for 6 weeks. The rats in sham operation group and remodeling model group were treated with normal sodium (with dose of 10 mL·kg-1·d-1 i.g) for 6 weeks. The rats in masculine medicine group were treated by Benazepril (with dose of 10 mg·kg-1 i.g) for 6 weeks. After 6 weeks of treatment,myocardial morphological parameters,the content of malondialdehyde (MDA) and activity of superoxide dismutase (SOD) in serum,the contents of prostacycline (PGI2),thromboxane A2 (TXA2),nitric oxide (NO) and angiotensinⅡ (AngⅡ) in plasma were determined. At the same time,the contents of endothelium (ET) in plasma and myocardium were also determined. Results Compared with remodeling model group,the ventricular weight and cardiac coefficient were decreased significantly in the rats treated with PQDS (P<0.05),the content of MDA in serum was declined and the activity of SOD in serum increased signficatly(P<0.05),the contents of AngⅡ and TXA2 in plasma were declined while the content of PGI2 in plasma and PGI2/TXA2 ratio were increased significatly (P<0.05 or P<0.01). In addition,the contents of ET in plasma and myocardium were also declined markedly (P<0.05 or P<0.01),but the content of NO in plasma had no significant change (P>0.05). Conclusion PQDS has protective effects on ventricular remodeling through increasing anti-oxidase activity,reducing the damage of free radicals and vasoactive substance on myocardium and correcting disequilibrium of PGI2/TXA2 in ventricular remodeling etc.