牛蒡子苷对小鼠原代骨骼肌细胞磷酸二酯酶活性及细胞生长的影响

 【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24 h，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2.5 μg?ml-1、茶碱终浓度为20 μg?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。

Effects of Arctiin On Phosphodiesterase Activity and Cell Growth in Mouse Primary Cultured Myocytes

【OBJECTIVE】To understand the mechanism of Chinese herbal medicine phosphodiesterase inhibitor to increase growth of muscle, theophylline used as reference, the effect of arctiin on phosphodiesterase (PDE) activity and protein synthesis of primary cultured myocytes was investigate;【METHOD】Myoblasts were isolated from 1-3-day-old newborn ICR mice limbs. The medium containing different concentration of arctiin and theophylline was added into cultured myocytes when myotubes were formed. After continuous incubation in incubator for 24 hours, cyclic adenosine 3’, 5’- monophosphate (cAMP) PDE activity, intracellular cAMP and cell total protein were assessed; 【RESULTS】The results were that cAMP PDE activity was most significantly inhibited (P<0.01）, intracellular cAMP level was greatly increased (P<0.05) and amount of cell total protein was most markedly accelerated (P<0.01) by arctiin and theophylline which concentration were respectively 2.5μg/ml and 20μg/ml in medium;【CONCLUSION】These results suggest that Chinese herbal medicine PDE inhibitor may increase skeletal muscle growth by inhibiting the activity of myocytes PDE to regulate the intracellular cAMP level and enhance protein synthesis.