ABSTRACT

Protein-containing nutrients result in the efficient hypertrophy of muscles by increasing muscle protein synthesis. Soybean is often ingested by athletes or individuals who exercise; however, it takes very long to be absorbed. Lactic acid-fermented and enzyme-digested (LFED) soybean is absorbed faster than untreated soybean. This study aims at determining muscle protein synthesis after ingesting a single bolus of soybean or LFED soybean produced by lactic acid bacteria and protease digestion. Eight-week-old overnight-fasted ICR mice were administered powdered or LFED soybean. Mice were euthanized at 7, 15, 30, 60, 90, and 120 min after soybean intake. We have demonstrated that LFED soybean administration was quicker in stimulating muscle protein synthesis by activating mammalian target of rapamycin (mTOR) signaling than orally ingesting untreated soybean in the gastrocnemius muscle. These results suggested that LFED soybean is a more efficient source of nutrition for muscle hypertrophy than untreated soybean.

摘要

含蛋白质的营养物质通过增加肌肉蛋白质的合成而导致肌肉的有效肥大。运动员或运动的人经常摄入大豆；但是，它需要很长时间才能被吸收。乳酸发酵和酶消化（LFED）的大豆比未处理的大豆吸收更快。这项研究的目的是确定摄取乳酸菌和蛋白酶消化产生的大剂量大豆或LFED大豆后的肌肉蛋白质合成。给八周大的过夜禁食的ICR小鼠服用粉状或LFED大豆。摄入大豆后第7、15、30、60、90和120分钟对小鼠实施安乐死。我们已经证明，相比口服未经处理的大豆腓肠肌，LFED大豆通过激活雷帕霉素（mTOR）信号传递的哺乳动物靶标，可以更快地刺激肌肉蛋白质合成。这些结果表明，与未经处理的大豆相比，LFED大豆是肌肉肥大的更有效的营养来源。