红景天对自发性高血压大鼠血压的调节及机制

目的:探讨藏药红景天对自发性高血压大鼠(SHR)血压的调节,并探讨其作用机制.方法:将13周龄雄性SHR适应饲养2周后随机分为5组,空白模型对照组(0.5％ CMC),藏药红景天高、中、低剂量组(生药i.08,0.27.0.068 g·kg-1·d-1),卡托普利组(0.015 g·kg-1·d-1),另设同龄正常血压的Wistar-kyoto(W KY)大鼠12只为WKY对照组(0.5％CMC),连续ig 4周,采用尾动脉测压法测量ig给药前和单次ig红景天12 h内及连续ig4周大鼠血压,检测大鼠血脂、血清一氧化氮(NO)含量、超氧化物歧化酶(SOD)活性及计算左心室质量指数(LVWI).结果:单次ig 12 h和连续ig 4周后各给药组收缩压较SHR模型组明显降低(P＜0.05,P＜0.01),而模型组收缩压明显高于WKY组(P＜0.01)；与模型组比较,红景天各给药组能降低SHR血清低密度脂蛋白-胆固醇(LDL-C)水平(P ＜0.05,P＜0.01),升高SHR血清高密度脂蛋白-胆固醇(HDL-C)水平及降低游离脂肪酸(FFA)的趋势,低剂量组可降低SHR血清总胆固醇(TC)水平(P＜0.05)；与模型组比较,红景天高、中剂量组NO含量有不同程度升高,红景天高、低剂量组SOD明显升高(P ＜0.05,P＜0.01),各给药组均能降低左心室质量指数.结论:藏药红景天可能通过调节脂代谢、升高NO含量、提高SOD活性及改善左室肥厚发挥对SHR大鼠的降压效应.

Regulating Effect and its Mechanism of Tibet Rhodiola crenulate on Blood Pressure in Spontaneous Hypertension Rat

Objective: To investigate the regulating effect and mechanism of the Tibet Rhodiola crenulata on blood pressure in spontaneous hypertension rat (SHR). Method: The male SHR of 13 weeks old were randomly divided into five groups: SHR control group(0.5%CMC), the high, middle, low dosage group of the R.Crenulata(crude drug 1.08, 0.27, 0.068 g·kg^-1·d^-1) and captopril group(0.015 g·kg^-1·d^-1).Twelve male Wistar-kyoto rats(WKY)were served as normal group(0.5%CMC).Different dose of Tibet R.Crenulata were administrated daily via gavage for 4 weeks.Systolic blood pressure(SBP) were measured respectively by tail-cuff technique before therapy,at the time after a single ig administration of Tibet R.Crenulata and at the time after amultiple ig adiministration. At end of the experiment, blood lipid parameters, the content of nitric oxide(NO),the activity of superoxide dismutase(SOD) were also detected and the ratios of left ventricle wet weight/body weigh left ventricutar mass index(LVMI) were calculated. Result: The SBP level of SHR in R. crenulata treatment groups was depressed notably(P<0.05-P<0.01),nevertheless the SBP level of SHR of model group was increased obviously comparing with normal group (P<0.01) at the time after a single ig administration of R. crenulata for 12 h and at the time after amultiple ig adiministration of Tibet R.Crenulata for 4 weeks. Compare with model group.The level of LDL-C was decreased significantly(P<0.05-P<0.01) in Rhodiola treatment groups.The level of HDL-C was obviously increased and the level of FFA was decreased significantly.The level of TC was decreased(P<0.05)in low-dose group of R.crenulata.The content of NO were increased significantly in high-dose and middle-dose group of R.Crenulata.The activity of SOD were increased significantly (P<0.05-P<0.01)in high-dose and low-dose group of R.Crenulata.LVMI were decreased significantly in R.Crenulata treatment groups. Conclusion: The hypotensive function of R. crenulata was significantly in SHR. Its mechanism may modulate the lipid metabolism,increase the content of NO,enhance the activity of SOD and improve left ventricular hypertrophy.