Wake S A, Sowden J A, Storlien L H, James D E, Clark P W, Shine J, Chisholm D J, Kraegen E W
Garvan Institute of Medical Research, St. Vincent's Hospital, Darlinghurst, New South Wales, Australia.
Diabetes. 1991 Feb;40(2):275-9. doi: 10.2337/diab.40.2.275.
Both exercise training and dietary manipulation (increasing omega-3/omega-6 fat ratio) can ameliorate insulin resistance caused by a high-fat diet in rats. We determined whether alterations in the expression of the insulin-regulatable (IR) and/or HepG2 glucose-transporter (GT) mRNAs were similarly affected. There was a significantly higher level of IRGT mRNA in skeletal muscle from exercise-trained versus sedentary high-fat-fed rats (27% increase, P less than 0.01). This difference is consistent with previously reported increases in muscle insulin-mediated glucose uptake. Skeletal muscle HepG2GT mRNA was too low to detect any training effect, but there was a tendency toward higher levels with training in cardiac muscle. In contrast, dietary manipulation, previously shown to lead to a much greater increase (100-300%) in muscle insulin-mediated glucose uptake, did not change IRGT or HepG2GT mRNA in skeletal muscle or heart. Thus, both dietary manipulation and exercise training increase insulin-stimulated glucose uptake in skeletal muscle, but only exercise training increases IRGT mRNA. Therefore, exercise training apparently increases GT production, whereas dietary manipulation improves glucose transport in skeletal muscle by other mechanisms.
运动训练和饮食调控（提高ω-3/ω-6脂肪比例）均可改善高脂饮食诱导的大鼠胰岛素抵抗。我们研究了胰岛素调节（IR）和/或HepG2葡萄糖转运体（GT）mRNA表达的改变是否也受到类似影响。与久坐的高脂喂养大鼠相比，运动训练的大鼠骨骼肌中IRGT mRNA水平显著更高（增加27%，P<0.01）。这一差异与先前报道的肌肉胰岛素介导的葡萄糖摄取增加一致。骨骼肌中HepG2GT mRNA水平过低，无法检测到任何训练效果，但心肌中随着训练有升高的趋势。相比之下，先前显示饮食调控可使肌肉胰岛素介导的葡萄糖摄取有更大幅度增加（100-300%），但并未改变骨骼肌或心脏中IRGT或HepG2GT mRNA水平。因此，饮食调控和运动训练均可增加骨骼肌中胰岛素刺激的葡萄糖摄取，但只有运动训练可增加IRGT mRNA。所以，运动训练明显增加GT生成，而饮食调控通过其他机制改善骨骼肌中的葡萄糖转运。
