Vinayaga Moorthi R, Bobby Zachariah, Selvaraj N, Sridhar M G
Department of Biochemistry, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry-605 006, India.
Clin Chim Acta. 2006 May;367(1-2):132-6. doi: 10.1016/j.cca.2005.12.004. Epub 2006 Feb 3.
The effect of reactive oxygen species (ROS) on insulin action is unclear. This study was carried out to explore the effect of prolonged low grade oxidative stress and vitamin E treatment on cultured rat L6 muscle cells.
L6 myotubes were incubated with vitamin E for 18 h and treated with H2O2 generating system for 12 h. Insulin stimulated glucose uptake, total antioxidant capacity and reduced glutathione concentration were measured.
There was a marked decrease in insulin stimulated glucose transport in L6 cells exposed to H2O2 generating system. Pretreatment with vitamin E attenuates the effect of H2O2 on insulin action. Treatment with H2O2 caused a significant reduction in the levels of reduced glutathione and total antioxidant capacity, these alterations were reversed by vitamin E pretreatment. Vitamin E per se had no effect on insulin stimulated glucose transport in cells not exposed to oxidative stress.
In conclusion, our observations indicate that vitamin E improves the free radical defense system potential and prevents oxidative stress induced insulin resistance in rat L6 muscle cells.
活性氧（ROS）对胰岛素作用的影响尚不清楚。本研究旨在探讨长期低度氧化应激及维生素E处理对培养的大鼠L6肌肉细胞的影响。
将L6肌管与维生素E孵育18小时，并用H2O2生成系统处理12小时。测量胰岛素刺激的葡萄糖摄取、总抗氧化能力和还原型谷胱甘肽浓度。
暴露于H2O2生成系统的L6细胞中，胰岛素刺激的葡萄糖转运显著降低。维生素E预处理可减弱H2O2对胰岛素作用的影响。H2O2处理导致还原型谷胱甘肽水平和总抗氧化能力显著降低，维生素E预处理可逆转这些改变。维生素E本身对未暴露于氧化应激的细胞中胰岛素刺激的葡萄糖转运没有影响。
总之，我们的观察结果表明，维生素E可提高自由基防御系统的潜力，并预防氧化应激诱导的大鼠L6肌肉细胞胰岛素抵抗。
