Insulin receptor substrate 2 content and tyrosine phosphorylation in diabetes mellitus rat skeletal muscle cells and the correlations with different densities of exercises
- VernacularTitle:糖尿病大鼠骨骼肌细胞胰岛素受体底物2含量及磷酸化变化与不同强度运动的关系
- Author:
Yongchun LI
- Publication Type:Journal Article
- From:
Chinese Journal of Tissue Engineering Research
2009;13(11):2183-2186
- CountryChina
- Language:Chinese
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Abstract:
BACKGROUND: Exercise can enhance the sensitivity and action effects of insulin. Its effects on insulin are closely related to skeletal muscle cell insulin receptor substrate 2 (IRS-2)-mediated function.OBJECTIVE: To investigate the effects of different densities of exercise on ISR-2 protein content and tyrosine phohorylation in diabetes mellitus rat skeletal muscle cells.DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the Laboratory of Physical Education institute of Liaoning Normal University between April and June 2008.MATERIALS: A total of 60 healthy Sprague-Dawley (SD) rats were randomly divided into 6 groups, with 10 rats per group: normal control, diabetes mellitus control, exercise intensity 15, 20, 25, and 30 m/min.METHODS: Diabetes mellitus was induced in rats by an intraperioneal injection of streptozocin in all groups except for the normal control group, in which, the same amount of citrate buffer solution was given. Diabetes mellitus rats were daily forced to do 50-minute exercise at an intensity of 15, 20, 25, or 30 m/min, 6 days a week, for a total of 6 weeks. Exercise was not given in the normal control and diabetes mellitus control groups. MAIN OUTCOME MEASURES: IRS-2 protein content and tyrosine phosphorylation in the rat skeletal muscle cells were examined by Western blot analysis.RESULTS: Compared with diabetes mellitus control group, IRS-2 content increased by 17%, 24.4%, 23.4%, and 21.3% in the 15, 20, 25, and 30 m/min groups accordingly (P<0.05 or P<0.01), and tyrosine phosphorytation of IRS-2 protein was enhanced by 34.7%, 37.2%, 40.2%, and 38.8% in these four groups (P<0.01), But the IRS-2 protein content and its tyrosine phosphorylation did not recover to levels of normal control group. There was no statistical significance in IRS-2 protein expression and tyrosine phosphorylation among exercise intensity 15, 20, 25, and 30 m/min groups.CONCLUSION: Under different intensities of exercise, IRS-2 protein content increases, in particular over 20 m/min, while the tyrosine phosphorylation of IRS-2 protein in skeletal muscle in diabetes mellitus rats is not affected.
