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背景:胰岛素诱导的离子运输改变可影响代谢调节,并且胰岛素抵抗条件下钠钾三磷酸腺苷酶活性的降低导致高血压以及糖原合成、葡萄糖氧化和ATP产生的减少。目的:观察钠钾三磷酸腺苷酶在胰岛素抵抗模型中的表达调控。设计:对照实验。单位:英国邓迪大学生命科学学院分子生理学系。材料:实验于1999-10/2000-02完成。使用15只体质量200～250g的清洁级成年雄性SpragueDawley大鼠。每次实验使用5只,相同实验重复3次。方法:去除大鼠一侧后肢神经支配,4d后将骨骼肌从去除神经支配的后肢和对侧对照后肢中解剖并分离,从红色肌肉(比目鱼与红色腓肠肌)和白色腓肠肌中分离粗制细胞膜。应用免疫印迹法和Northern杂交分析法分别检测蛋白质和mRNA的表达。使用Bio-RadGS-670图像密度仪对蛋白质和mRNA的信号强度进行定量。主要观察指标:对照侧和去除神经支配后肢骨骼肌中钠钾三磷酸腺苷各亚基蛋白质和mRNA表达水平的比较。结果:15只大鼠全部进入结果分析。与对照侧相比,去除神经支配的后肢中:①红色骨骼肌中α2和β1亚基的蛋白质表达分别下降46%和77%。在红色和白色骨骼肌中,α1亚基的蛋白质表达分别增加了20%和15%。β2亚基的蛋白质表达在红色和白色骨骼肌中均未发生显著变化。②在红色腓肠肌和比目鱼肌中,α2亚基的mRNA水平分别下降了29%和39%,β1亚基的mRNA水平分别下降了80%和52%。在红色和白色腓肠肌中,α1亚基的mRNA水平分别增加了9倍和1.3倍。β2亚基的mRNA水平在红色腓肠肌中无显著变化,但在白色腓肠肌中减少了59%。结论:①在去除神经支配的大鼠骨骼肌中,钠钾三磷酸腺苷酶各亚基的表达受转录和转录后双重调控。②α2和β1亚基的蛋白质表达显著下降的结果提示,在大鼠骨骼肌中,去除神经支配造成的胰岛素抵抗使原本受胰岛素调节的钠钾三磷酸腺苷酶亚基的表达机制被破坏。
BACKGROUND: Insulin-induced changes in ion transport can affect metabolic regulation and reduction of Na + -ATPase activity under insulin resistance leads to hypertension and reduction of glycogen synthesis, glucose oxidation and ATP production. Objective: To observe the expression and regulation of sodium and potassium adenosine triphosphatase in insulin resistance model. Design: Control experiment. Unit: Department of Molecular Physiology, College of Life Sciences, University of Dundee, UK. Material: The experiment was completed in 1999-10 / 2000-02. Fifteen clean male adult Sprague Dawley rats of 200-250 g body weight were used. 5 for each experiment, the same experiment repeated 3 times. Methods: The innervation of the hind limbs on one side of the rats was removed. After 4 days, the skeletal muscles were dissected and separated from the denervated hindlimbs and contralateral control hindlimbs. The crude cell membranes were separated from the red muscles (flatfish and red gastrocnemius) and white gastrocnemius muscle. Western blotting and Northern blotting were used to detect the protein and mRNA expression respectively. Protein and mRNA signal intensities were quantified using a Bio-RadGS-670 image densitometer. MAIN OUTCOME MEASURES: Comparison of protein and mRNA expression levels of sodium and potassium adenosine triphosphate subunits in skeletal muscle of control and denervated hind limbs. Results: All 15 rats entered the result analysis. In denervated hindlimbs compared to the control side: ① The protein expression of α2 and β1 subunits in red skeletal muscle decreased by 46% and 77%, respectively. In red and white skeletal muscle, α1 subunit protein expression increased by 20% and 15% respectively. Protein expression of the β2 subunit did not change significantly in both red and white skeletal muscle. ② In the red gastrocnemius and soleus muscle, mRNA levels of α2 subunit decreased by 29% and 39%, respectively, and β1 subunit mRNA levels decreased by 80% and 52%, respectively. In the red and white gastrocnemius muscles, the α1 subunit mRNA levels increased 9-fold and 1.3-fold, respectively. The mRNA level of the β2 subunit did not change significantly in the red gastrocnemius muscle but decreased by 59% in the white gastrocnemius muscle. Conclusion: (1) In the denervated rat skeletal muscle, the expression of each subunit of Na + and K + -ATPase is regulated by both transcription and transcription. ② The results of the significant decrease of the protein expression ofα2 and β1 subunits suggest that the insulin resistance induced by denervation in rat skeletal muscle disrupts the expression mechanism of natriuretic potassium and adenosine triphosphate subunits.