圣地红景天对自发性高血压大鼠左室重构的影响及其机制探讨

目的 探讨圣地红景天对自发性高血压大鼠(SHR)左室重构的影响。 方法 将30只雄性SHR随机分为治疗组与对照组,分别予以圣地红景天500 mg/(kg·d)和蒸馏水灌胃,共8周,每两周测尾动脉收缩压(SBP)一次。实验结束时,测量大鼠体质量(BM)与左室质量(LVM),计算左室质量指数(LVMI=LVM/BM);采用放射免疫法分别测定血浆与心肌组织匀浆上清液中血管紧张素Ⅱ(AngⅡ)、醛固酮(ALD)以及心肌组织匀浆上清液蛋白含量,计算心肌匀浆上清液每克蛋白AngⅡ与ALD含量;将左室心肌切片分别进行胶原染色及免疫组化技术处理,用Simple PCI全自动图像分析系统检测心肌胶原容积分数(CVF)、心肌细胞AngⅡ1型受体(AT₁)灰度值。 结果 与对照组比较,治疗组SBP下降(P<0.05)、LVMI(mg/g,2.84±0.13 vs.2.97±0.12,P=0.044)、心肌CVF(%,4.41±0.53 vs.4.89±0.53,P=0.021)、血浆AngⅡ(ng/L,77.61±14.12 vs.92.59±16.64,P=0.042)与ALD(ng/L,73.52±18.61 vs.90.11±19.67,P=0.005)、心肌组织匀浆上清液中AngⅡ(ng/g·protein,40.03±5.36 vs.46.02±6.78,P=0.005)与ALD(ng/g·protein,37.61±6.25 vs.43.70±5.09,P=0.049)均降低。而圣地红景天对心肌细胞AT₁蛋白表达的影响与对照组比较差异无统计学意义。 结论 圣地红景天可改善SHR左室重构,其机制与降压作用、肾素-血管紧张素系统(RAS),特别是心肌局部RAS的受抑有关。

Effect of Rhodiola Sacra on Left Ventricular Remodeling and Its Mechanism in Spontaneously Hypertensive Rats

Objective To investigate the effect of Rhodiola Sacra on left ventricular remodeling in spontaneously hypertensive rats (SHRs). Methods 30 male SHRs were randomly allocated into a treatment and a control group, which were intragastric administered with Rhodiola Sacra 500 mg/(kg·d) and water respectively. Tail systolic blood pressure (SBP) was monitored every two weeks. After 8 weeks, the body mass (BM) and left ventricle mass (LVM) of the rats were measured for computing the left ventricle mass index (LVMI). Plasma and myocardial homogenate angiotensin Ⅱ (AngⅡ), aldosterone (ALD) and the protein of myocardial homogenate were detected respectively by radioimmunoassay, and then the quantity of AngⅡ and ALD per gram protein was calculated. Myocardial specimen slides were stained with method of Masson staining, and myocardial collagen volume fraction (CVF) was calculated by a Computer Image System. Protein expression of AngⅡ type 1 receptor (AT₁) in left ventricular myocardium were detected by immunohistochemistry technique, and calculated by a Computer Image System. Results Compared with the control group, there was a obvious decrease in SBP (P<0.05), LVMI (mg/g, 2.84±0.13 vs. 2.97±0.12, P=0.044), myocardial CVF (%,4.41±0.53 vs. 4.89±0.53, P=0.021), plasma AngⅡ (ng/L, 77.61±14.12 vs. 92.59±16.64, P=0.042), plasma ALD (ng/L, 73.52±18.61 vs. 90.11±19.67, P=0.005), myocardial AngⅡ (ng/g·protein, 40.03±5.36 vs. 46.02±6.78, P=0.005) or myocardial ALD (ng/g·protein, 37.61±6.25 vs. 43.70±5.09, P=0.049), whereas no significant difference was observed in the protein expression of AT₁ in left ventricular myocytes between the two groups. Conclusion Rhodiola Sacra may prevent left ventricular remodeling in SHRs, which is probably attributed to blood pressure lowering and inhibition of RAS, especially myocardial RAS.