荞麦花叶总黄酮对实验性大鼠心肌肥厚的保护作用

目的 探讨荞麦花叶总黄酮(TFBFL)对去甲肾上腺素所致大鼠心肌肥厚的保护作用及其可能的机制.方法 将大鼠随机分为6组(n=12)空白对照组,肥厚模型组,TFBFL Ⅰ、Ⅱ、Ⅲ组,和卡托普利治疗组(Cap组).用去甲肾上腺素(NE)腹腔注射1.5 mg(kg·d),Bid,建立大鼠心肌肥厚模型,同时TFBFL和Cap 灌胃给药100、200、400和50mg/(kg·d),o.d.,连续15 d.观察心电图(ECG),左心室肥厚指数(LVWIlvw/bw),和心重指数(HWIhw/bw,lvw/hw).采用比色法测定心室肌钙含量,用放免分析法检测血浆、心肌、肾脏血管紧张素Ⅰ(Ang Ⅰ)生成率(反映肾素活性)和血管紧张素Ⅱ(AngⅡ)含量.结果 与肥厚模型组比,TFBFL能剂量依赖性的改善心肌肥厚大鼠的ECG,降低LVWI和HWI,心肌钙含量和心肌Ang Ⅱ含量,但对血浆肾脏Ang Ⅱ含量无明显影响和心肌、血浆和肾脏AngⅠ生成率均无明显影响,且与阳性药物卡托普利组治疗效果相近.结论 荞麦花叶总黄酮对大鼠心肌肥厚具有保护作用,其机制可能与拮抗心肌局部肾素-血管紧张素(RAS)系统有关.

Protection of total flavones of buckwheat flower and leaf on experimental cardiac hypertrophy in rats

[Objective] To study the protection of total flavones of buckwheat flower and leaf (TFBFL) on experimental cardiac hypertrophy induced by norepinephrine (NE) and its mechanism. [Methods] To divide the rats randomly into Mowing 6 groups(n =12 per group): (A)control, (B) hypertrophy, (C)TFBFL Ⅰ , (D)TFBFLⅡ, (E)TFBFL Ⅲ and(F)captopril. To establish the cardiac hypertrophy models of rats by ip of NE and observe the EGG, the left ventricular mass index (LVMI:lvw/bw) and the heart weight index(HWT:hw/bw,lvw/hw). The angiotensin Ⅰ (Ang Ⅰ ) production rate (reflecting rennin activity) and angiotensin Ⅱ (Ang Ⅱ) content of plasma, myocardium and kidney tissue were measured by radioimmunoassay and myocardium Ca2+ by colorimetry. [Results] Compared with hypertrophy group, TFBFL could protect against cardiac hypertrophy of rats in a dose-dependent manner, such as improved EGG, LVWI and HWI, obviously decreased cardiac Ca2+ content, cardiac Ang Ⅱ content was decreased significantly without the same change of plasma and kidney tissue, and had similar relation with the treatment of captropril. [Conclusion] TFBFL has some profective effects on NE-indused cardiac hypertrophy in rats. The mechanism may be related to inhibition of local myocardium rennin angiotensin aldsteron system.