Schnuck Jamie K, Sunderland Kyle L, Kuennen Matthew R, Vaughan Roger A
Department of Exercise Science, High Point University, High Point North Carolina U.S.A.
J Exerc Nutrition Biochem. 2016 Jun;20(2):34-41. doi: 10.20463/jenb.2016.06.20.2.5. Epub 2016 Jun 30.
β-alanine is a common component of numerous sports supplements purported to improve athletic performance through enhanced carnosine biosynthesis and related intracellular buffering. To date, the effects of β-alanine on oxidative metabolism remain largely unexplored. This work investigated the effects of β-alanine on the expression of proteins which regulate cellular energetics.
C2C12 myocytes were cultured and differentiated under standard conditions followed by treatment with either β-alanine or isonitrogenous non-metabolizable control D-alanine at 800μM for 24 hours. Metabolic gene and protein expression were quantified by qRT-PCR and immunoblotting, respectively. Glucose uptake and oxygen consumption were measured via fluorescence using commercially available kits.
β-alanine-treated myotubes displayed significantly elevated markers of improved oxidative metabolism including elevated peroxisome proliferator-activated receptor β/δ (PPARβ/δ) and mitochondrial transcription factor a (TFAM) which led to increased mitochondrial content (evidenced by concurrent increases in cytochrome c content). Additionally, β-alanine-treated cells exhibited significantly increased oxygen consumption compared to control in a PPARβ/δ-dependent manner. β-alanine significantly enhanced expression of myocyte enhancer factor 2 (MEF-2) leading to increased glucose transporter 4 (GLUT4) content.
β-alanine appears to increase cellular oxygen consumption as well as the expression of several cellular proteins associated with improved oxidative metabolism, suggesting β-alanine supplementation may provide additional metabolic benefit (although these observations require in vivo experimental verification).
β-丙氨酸是众多运动补剂的常见成分，据称可通过增强肌肽生物合成及相关细胞内缓冲作用来提高运动表现。迄今为止，β-丙氨酸对氧化代谢的影响在很大程度上仍未得到探索。本研究调查了β-丙氨酸对调节细胞能量代谢的蛋白质表达的影响。
将C2C12肌细胞在标准条件下培养并分化，随后用800μM的β-丙氨酸或等氮不可代谢对照D-丙氨酸处理24小时。分别通过qRT-PCR和免疫印迹法对代谢基因和蛋白质表达进行定量。使用市售试剂盒通过荧光法测量葡萄糖摄取和耗氧量。
经β-丙氨酸处理的肌管显示出氧化代谢改善的显著升高标志物，包括过氧化物酶体增殖物激活受体β/δ（PPARβ/δ）和线粒体转录因子a（TFAM）升高，这导致线粒体含量增加（细胞色素c含量同时增加证明）。此外，与对照组相比，经β-丙氨酸处理的细胞以PPARβ/δ依赖性方式表现出显著增加的耗氧量。β-丙氨酸显著增强了肌细胞增强因子2（MEF-2）的表达，导致葡萄糖转运蛋白4（GLUT4）含量增加。
β-丙氨酸似乎增加了细胞耗氧量以及与改善氧化代谢相关的几种细胞蛋白质的表达，这表明补充β-丙氨酸可能提供额外的代谢益处（尽管这些观察结果需要体内实验验证）。
