中文摘要：

【目的】以茶碱为参照,观察中药成分牛蒡子苷对原代骨骼肌细胞磷酸二酯酶（Phosphodiesterase,PDE）活性及蛋白质合成的影响,探讨中药通过抑制PDE促进肌肉生长的作用及机理。【方法】分离1～3日龄ICR小鼠四肢肌肉用于骨骼肌原代细胞培养,在培养至第5～6天时向培养基中添加不同浓度的牛蒡子苷和茶碱,以不含牛蒡子苷和茶碱的培养基为阴性对照,继续培养24h,采用HPLC、ELISA以及考马斯亮蓝法分别测定骨骼肌细胞cAMP PDE的活性、细胞内cAMP水平以及细胞总蛋白质合成。【结果】牛蒡子苷终浓度达到2.5μg·ml^-1、茶碱终浓度为20μg·ml^-1时均能极显著抑制原代培养骨骼肌细胞cAMP PDE的活性（P〈0.01）,显著提高细胞内cAMP水平（P〈0.05）,极显著促进肌细胞总蛋白质的合成（P〈0.01）。【结论】中药成分牛蒡子苷具有通过调节骨骼肌细胞内PDE的活性和cAMP水平,增加肌细胞蛋白质合成,促进骨骼肌细胞生长的作用。结果提示对PDE有抑制作用的中药有望成为促进动物生长的新型饲料添加剂。

英文摘要：

[Objective] To understand the mechanism of Chinese herbs＇ medicinal effect on increasing growth of muscle by inhibiting phosphodiesterase （PDE）, the effects of arctiin on PDE activity and protein synthesis of primary cultured myocytes was investigated using theophylline as reference. [Method] Myoblasts were isolated from 1-3-day-old newborn ICR mice limbs for culture of primary skeletal muscle cells. The medium containing different concentration of arctiin and theophylline was added into cultured myocytes on the 5-6th day. After 24 hours＇ incubation, cyclic adenosine 3′, 5′- monophosphate （cAMP） PDE activity, intracellular cAMP and cell total protein were assessed by HPLC, ELISA and Coomassie brilliant blue G-250-binding method, respectively. [Result] cAMP PDE activity was significantly inhibited （P〈0.01）, intracellular cAMP level （P〈0.05） and amount of cell total protein was markedly increased （P〈0.01） with arctiin and theophylline concentration of 2.5μg·ml^-1 and 20μg·ml^-1 respectively in medium. [ Conclusion] These results suggest that arctiin which is a main component of Fructus Arctii increase skeletal muscle growth by inhibiting the activity of myocytes PDE to regulate the intracellular cAMP level and enhance protein synthesis. In addition, Chinese herbal medicine which inhibits PDE may become a new type of agent for increase of animal growth rate.