目的 研究葛根素对舒张性心力衰竭（distolic heart failure，DHF）大鼠心肌僵硬度和心肌组织Ⅰ型、Ⅲ型胶原表达的影响。方法 Wistar大鼠腹主动脉缩窄法建立DHF模型，术后4周，随机分为4组（n=10），模型组，葛根素高、中、低剂量组（180、120、80 mg/kg），另有假手术组10只。连续给予相应处理4周后，通过十六导生理记录仪测量所得的血流动力学指标计算大鼠心肌僵硬度常数（K），并应用免疫组化法测定心肌组织Ⅰ、Ⅲ型胶原的表达。结果 与模型组比较，葛根素高剂量组K值无变化（P＞0.05），中剂量组K值显著低于模型组（P＜0.01），低剂量组K值明显低于模型组（P＜0.05）。与模型组比较，葛根素高剂量组心肌I型胶原蛋白表达明显减弱（P＜0.05），心肌Ⅲ型胶原表达明显增强（P＜0.05）；中剂量组心肌I型胶原蛋白表达显著减弱（P＜0.01），心肌Ⅲ型胶原蛋白表达显著增强（P＜0.01）；低剂量组心肌I型胶原蛋白表达明显减弱（P＜0.05），心肌Ⅲ型胶原表达明显增强（P＜0.05）。结论 葛根素中、低剂量能够降低DHF大鼠心肌僵硬度，其作用机制与心肌Ⅰ型胶原、Ⅲ型胶原的表达有关。

Objective To study the effects of different doses of puerarin on stiffness in myocardium and expression of collagen type I and Ⅲ in diastole heart failure (DHF) rat models. Method DHF models were established by narrowing abdominal aorta in wistar rats. Four weeks after operation, DHF rats were divided into four groups randomly as follows, model group, puerarin high-, mid-, and low-dose groups (180, 120, 80 mg/kg), and sham operation group (n=10). After four-week administration, the stiffness of rat cardiac (K) was calculated by hemodynamics which measured by 16 physiologic recorder. The expression of collagen type I and Ⅲ was examined by immunohistochemical method. Results Compared with model group, K of the puerarin high-dose group did not change (P>0.05), K of the mid-dose group was significantly lower (P<0.01), K of the low-dose group was significantly lower (P<0.05). Compared with model group, the expression of collagen type I was significantly decreased (P<0.05), type Ⅲ was significantly enhanced (P<0.05) in puerarin high-dose group. The expression of collagen type I was significantly decreased (P<0.01), type Ⅲ was significantly enhanced (P<0.01) in puerarin mid-dose group. The expression of collagen typeⅠwas decreased significantly (P<0.05), type Ⅲ was significantly enhanced (P<0.05) in puerarin low-dose group. Conclusion Puerarin of middle and low doses could improve myocardial stiffness of DHF rats, and its mechanism is related with the expression of collagen type I and Ⅲ.