Department of Food Science and Human Nutrition, Iowa State University, Ames, Iowa 50011, USA.
Nutr Res. 2013 Jun;33(6):487-93. doi: 10.1016/j.nutres.2013.04.008. Epub 2013 May 18.
Hyperhomocysteinemia is a condition that results from altered methyl group metabolism and is associated with numerous pathological conditions. A number of nutritional and hormonal factors have been shown to influence circulating homocysteine concentrations; however, the impact of exercise on homocysteine and methyl group balance is not well understood. Our hypothesis was that exercise represents an effective means to prevent hyperhomocysteinemia in a folate-independent manner. The purpose of this study was to determine the influence of exercise on homocysteine metabolism in a dietary folate-restricted mouse model characterized by moderate hyperhomocysteinemia. Female outbred mice (12 weeks old) were assigned to either a sedentary or free-access wheel exercise group. Following a 4-week acclimation period, half of the mice in each group were provided a folate-restricted diet for 7-weeks prior to euthanasia and tissue collection. As expected, folate-restricted sedentary mice exhibited a 2-fold increase in plasma total homocysteine concentrations; however, exercise completely prevented the increase in circulating homocysteine concentrations. Moreover, exercise reduced plasma homocysteine concentrations 36% within the group fed only the control diet. The prevention of hyperhomocysteinemia by exercise appears, at least in part, to be the result of increased folate-independent homocysteine remethylation owing to a 2-fold increase in renal betaine homocysteine S-methyltransferase. To our knowledge, this is the first report demonstrating the prevention of hyperhomocysteinemia by exercise in a dietary folate-restriction model. Future research will be directed at determining if exercise can have a positive impact on other nutritional, hormonal, and genetic models of hyperhomocysteinemia relevant to humans.
高同型半胱氨酸血症是一种由于甲基化代谢改变而导致的病症，与许多病理状况有关。许多营养和激素因素已被证明会影响同型半胱氨酸的循环浓度；然而，运动对同型半胱氨酸和甲基化平衡的影响还不是很清楚。我们的假设是，运动是一种以叶酸独立的方式预防高同型半胱氨酸血症的有效方法。本研究的目的是确定运动对叶酸限制的饮食模型中同型半胱氨酸代谢的影响，该模型表现为中度高同型半胱氨酸血症。将 12 周龄的雌性杂交鼠分为久坐或自由轮式运动组。经过 4 周的适应期后，每组的一半小鼠在安乐死和组织收集前接受叶酸限制饮食 7 周。正如预期的那样，叶酸限制的久坐小鼠的血浆总同型半胱氨酸浓度增加了 2 倍；然而，运动完全阻止了循环同型半胱氨酸浓度的增加。此外，运动使仅喂食对照饮食的组的血浆同型半胱氨酸浓度降低了 36%。运动对高同型半胱氨酸血症的预防作用至少部分归因于肾脏甜菜碱同型半胱氨酸 S-甲基转移酶增加 2 倍导致叶酸独立的同型半胱氨酸再甲基化增加。据我们所知，这是第一个在叶酸限制饮食模型中证明运动预防高同型半胱氨酸血症的报告。未来的研究将致力于确定运动是否对与人类相关的其他营养、激素和遗传的高同型半胱氨酸血症模型产生积极影响。
