The Effects of Low-Methionine Diet and Exercise Training on Antioxidant Capacity of Cardiac Tissues in Ovariectomized Rats

• Main Authors: Cheng, Hsin Yao, 鄭新耀
• Other Authors: Tsai, Shiow-Chwen
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/36666233483387327765

碩士 === 臺北巿立體育學院 === 運動科學研究所 === 101 === Abstract Ageing is the unavoidable process of human, and women would be non-reproductive and lack estrogen to cause menopause. Postmenopausal women will lead to higher oxidative stress, declined metabolism, and degenerate physiological function. The previously researches demonstrated that diet restriction and exercise could be beneficial to antioxidant capacity and cardiac function. The influence of low methionine combined exercise training in postmenopausal rats of heart is still unclear. The purpose is to investigate the effect of low methionine diet and exercise training on left ventricle of ovariectomized middle-aged female rats. In this study, female Sprague-Dawley (SD) rats of 35 weeks were subjected to sham or ovariectomy (Ovx) and divided into six groups according to the treatments, which were the Sham (treat as control group), Ovx+0.86% Met+sedentary, Ovx+0.172% Met+sedentary, Ovx+0.86% Met+Ex, Ovx+0.172% Met+Ex, Ovx+E2 (treat as a positive control group). A treadmill exercise was set for training groups with a regime of 16 m/min for 60 min/day, 5 days per week for 12 weeks. The left ventricle tissue were collected and analyzed for the production of lipid peroxidation (TBARS), and activities of antioxidant enzymes by using commercial kits. Protein expression was analyzed by Western blotting. All values were presented as the mean ± standard error of the mean (SEM). Means were tested for homogeneity by one-way ANOVA, and the difference between specific means was tested for significance by Duncan multiple-range test. The difference between two means were considered statistically significant when p<0.05. The results showed that Ovx+0.172% Met+Ex significantly decreased body and LV weight when compared with sham group. The production of lipid peroxidation in Ovx group, Ovx+0.172 % Met, Ovx+Ex, Ovx+0.172% Met+Ex, and Ovx+E2 were significant lower than sham group. The activity of SOD and catalase and the production of GSH and GSSG were significantly higher in Ovx+0.172% Met+Ex than in sham group (p<0.01). The protein expression of CuZnSOD and Catalase were higher in Ovx+0.172% Met+Ex. Ovariectomy reduced the protein expression significantly, supplementation of estradiol recovered the expression of IGF-1 receptor. Combination of low methionine and exercise training raised connexin 43 protein expression when compared with sham group. Exercise training induced higher expression of autophagy protein LC-3 than sham group. In conclusion, our results demonstrate that low methionine diet decreased apoptosis, exercise training accelerated autophagy. Combined low methionine diet and exercise training produced the benefits but also reduced the oxidative stress in cardiac tissues. For postmenopausal women, the research could provide an non-pharmacological and effective strategy to promote healthy life.