Department of Physiology and Pharmacology, Karolinska Institutet, 11486 Stockholm, Sweden.
Cell Metab. 2011 Feb 2;13(2):149-59. doi: 10.1016/j.cmet.2011.01.004.
Nitrate, an inorganic anion abundant in vegetables, is converted in vivo to bioactive nitrogen oxides including NO. We recently demonstrated that dietary nitrate reduces oxygen cost during physical exercise, but the mechanism remains unknown. In a double-blind crossover trial we studied the effects of a dietary intervention with inorganic nitrate on basal mitochondrial function and whole-body oxygen consumption in healthy volunteers. Skeletal muscle mitochondria harvested after nitrate supplementation displayed an improvement in oxidative phosphorylation efficiency (P/O ratio) and a decrease in state 4 respiration with and without atractyloside and respiration without adenylates. The improved mitochondrial P/O ratio correlated to the reduction in oxygen cost during exercise. Mechanistically, nitrate reduced the expression of ATP/ADP translocase, a protein involved in proton conductance. We conclude that dietary nitrate has profound effects on basal mitochondrial function. These findings may have implications for exercise physiology- and lifestyle-related disorders that involve dysfunctional mitochondria.
硝酸盐是一种在蔬菜中含量丰富的无机阴离子，在体内转化为具有生物活性的氮氧化物，包括一氧化氮。我们最近的研究表明，饮食中的硝酸盐可以降低运动时的氧气消耗，但具体机制尚不清楚。在一项双盲交叉试验中，我们研究了饮食干预无机硝酸盐对健康志愿者基础线粒体功能和全身耗氧量的影响。补充硝酸盐后提取的骨骼肌线粒体显示氧化磷酸化效率（P/O 比）提高，在有和没有阿托酸苷的情况下状态 4 呼吸和无腺嘌呤呼吸减少。改善的线粒体 P/O 比与运动时氧气消耗的减少相关。从机制上讲，硝酸盐降低了参与质子传导的 ATP/ADP 转运蛋白的表达。我们得出结论，饮食中的硝酸盐对基础线粒体功能有深远的影响。这些发现可能对涉及功能失调线粒体的运动生理学和与生活方式相关的疾病有影响。
