| （1.华南师范大学 体育科学学院，广东 广州 510006；2.广东省体育科学研究所，广东 广州 510100） 摘 要：棕榈酸孵育C2C12细胞建立富脂性胰岛素抵抗骨骼肌细胞模型，观察一定强度的电刺激引发收缩对其糖代谢的影响。选用不同梯度浓度的棕榈酸孵育分化5 d的C2C12细胞16 h，检测各组细胞培养液中葡萄糖剩余量和细胞活性，选取合适的棕榈酸浓度建立其诱导的胰岛素抵抗细胞模型。随后实验分为4组：对照组(C组)、电刺激组(EPS组)、棕榈酸组(PA组)、电刺激+棕榈酸组(EPS+PA组)，以15 V、30 ms、2 Hz的强度电刺激60 min，收样测定细胞培养液葡萄糖剩余量、AMPK-α2 mRNA和GLUT4蛋白表达量。结果显示，(1)0.5 mmol/L棕榈酸溶液孵育16 h，与C组相比，LDH、MTT无显著变化(P>0.05)，葡萄糖剩余量明显增加(P<0.05)，加入胰岛素刺激后，葡萄糖剩余量与刺激前相比无显著性差异(P>0.05)；(2)与C组相比，PA组葡萄糖剩余量显著增加(P<0.05)、AMPK-α2基因表达显著下降(P<0.05)、总GLUT4蛋白和膜GLUT4蛋白表达量显著下降(P<0.05)；(3)与PA组相比，EPS+PA组葡萄糖剩余量显著减少(P<0.05)、AMPK-α2基因表达显著升高(P<0.05)、肌管膜GLUT4蛋白表达量非常显著增加(P<0.01)、总GLUT4蛋白量虽有所增加，但无显著性变化(P>0.05)。结果说明：棕榈酸(0.5 mmol/L)孵育分化5 d的C2C12细胞16 h，可以导致其富脂性胰岛素抵抗的发生。15 V、30 ms、2 Hz的强度电刺激60 min，可以提高胰岛素抵抗骨骼肌细胞对葡萄糖的吸收，增加AMPK-α2mRNA和GLUT4蛋白的表达，有助于改善富脂性胰岛素抵抗骨骼肌细胞的糖代谢。 |
PAN Hong-ying1，XU Xiao-yang1，JIA Zhang-zhi2
| （1.School of Physical Education，South China Normal University，Guangzhou 510006，China；2. Sports Science Research Institute of Guangdong Province，Guangzhou 510100，China) Abstract: By using palmitic acid to incubate C2C12 cells, the authors established a model of lipid rich insulin resisting skeletal muscle cells, so as to observe the effects of contraction triggered by a certain intensity of electric stimulation on the cells’ sugar metabolism. The authors used different gradient concentrations of palmitic acid to incubate 5d differen-tiated C2C12 cells for 16h, measured glucose remaining amount and cell activity in the cell culture fluid of various groups, selected an appropriate palmitic acid concentration to establish a model of insulin resisting the cells, which was induced by such a concentration, then divided the experiment into 4 groups: a control group (C), an electric stimulation group (EPS), a palmitic acid group (PA), and an electric stimulation + palmitic acid group (EPS+PA ), applied an inten-sity of (15 V, 30 ms, 2 Hz) of electric stimulation for 60min, collected the samples and measured glucose remaining amount, AMPK-α2 mRNA and GLUT4 protein expression levels in the cell culture fluid, and revealed the following findings: 1) Comparing the group incubated with 0.5 mmol/L palmitic acid for 16 h with group C, LDH and MTT had no significant change (P>0.05), glucose remaining amount increased significantly (P<0.05), after adding insulin stimu-lation, glucose remaining amount had no significant difference as compared with that before stimulation (P>0.05); 2) Comparing group PA with group C, glucose remaining amount increased significantly (P<0.05), AMPK-α2 gene ex-pression decreased significantly (P<0.05), total GLUT4 protein and membrane GLUT4 protein expression levels de-creased significantly (P<0.05); 3) Comparing group EPS+PA with group PA, glucose remaining amount decreased sig-nificantly (P<0.05), AMPK-α2 gene expression increased significantly (P<0.05), myotube membrane GLUT4 protein expression level increased very significantly (P<0.01), total GLUT4 protein content had no significant change (P>0.05), although increased somewhat. The said findings indicate the followings: using palmitic acid (0.5 mmol/L) to incubate 5 d differentiated C2C12 cells for 16 h can cause the occurrence of resistance of their lipid rich insulin; an in-tensity of (15 V, 30 ms, 2 Hz) of electric stimulation for 60min can promote insulin resisting the glucose absorption by skeletal muscle cells, increase AMPK-α2 mRNA and GLUT4 protein expression, thus help improving lipid rich insulin resisting the sugar metabolism of skeletal muscle cells. |
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