加味镇眩颗粒对自发性高血压大鼠血压及血管内皮功能的影响

目的 观察加味镇眩颗粒对自发性高血压大鼠(SHR)血压、一氧化氮的合成和生物利用途径以及血管紧张素Ⅱ(AngⅡ)含量的影响.方法 将50只SHR大鼠随机分为加味镇眩颗粒高、中、低剂量组(给予37.50,18.70,9.35 g/kg)、卡托普利组(25 mg/kg)、SHR组(给予等体积蒸馏水),均为灌胃给药,经过12 w的干预治疗,分别测定大鼠的基础血压和4、8、12周的血压,实验结束后检测血浆一氧化氮(NO)和AngⅡ的含量,以及主动脉一氧化氮合酶(NOS)的活性、环磷酸鸟苷(cGMP)的含量.结果 加味镇眩颗粒可降低SHR血压,提高SHR血浆NO含量、主动脉NOS活性和主动脉cGMP含量,降低血浆Ang Ⅱ含量,与SHR组相比,差异具有显著性(P<0.05),其中,加味镇眩颗粒高剂量组的效果最好.12周时,加味镇眩颗粒高剂量组与卡托普利组降压效果相当,且增加主动脉cGMP含量效果更佳(P<0.05),并能提高NO的生物利用度.结论 加味镇眩颗粒能够降低SHR大鼠血压,可能是通过改善SHR大鼠NO/NOS/cGMP系统和降低Ang Ⅱ水平来发挥作用.

Effects of Modified Zhenxuan Granules on Blood Pressure and Endothelial Function of Spontaneously Hypertensive Rats

Objective To observe the effect of Modified Zhenxuan Granules (MZG) on blood pressure, synthesis and bioavail-ability of nitric oxide (NO), and plasma angiotensin I1 (Ang II) contents of spontaneously hypertensive rats (SHR). Methods Fiftymale SHR were randomly assigned to 5 groups: high-, middle-and low-dose MZG groups(at the doses of 37.50, 18. 70,and 9. 35 g/kg respectively), captopril (25 mg/kg) group and SHR control group. The rats received gastric gavage of corre-sponding medicine according to the experimental design for 12 weeks. Blood pressure from the tail was recorded at the beginning oftreatment and every 4 weeks during 12-weeks treatment. At the end of the experiment, the plasma NO and Ang II concentration,and aortal nitric oxide synthase (NOS) activity and aortal cyclic guanylic acid (cGMP) concentration were measured. ResultsMZG could decrease blood pressure and plasma Ang I1 concentration, increase plasma NO content, and enhance aortal NOS activ-ity and cGMP concentration ofSHR (P <0. 05, compared with the SHR control group), and high-dose MZG had the best effect.After treatment for 12 weeks, high-dose MZG had a similar effect on decreasing blood pressure compared with captoril group,had a better effect on increasing aortal cGMP (P< 0. 05), and increased the bioavailability of NO. Conclusion MZG can de-crease blood pressure, and its mechanism may be related to the improvement of NO/NOS/eGMP system and the decrease of plas-ma Ang Ⅱ concentration in SHR.