Department of Health Sciences and Human Performance, The University of Tampa, 401 W. Kennedy Blvd., Box 30 F, Tampa, FL 33606, USA.
Department of Comparative Biosciences, University of Wisconsin-Madison, Madison, WI, USA.
Nutr Metab (Lond). 2014 Jun 16;11:29. doi: 10.1186/1743-7075-11-29. eCollection 2014.
The lipid messenger phosphatidic acid (PA) plays a critical role in the stimulation of mTOR signaling. However, the mechanism by which PA stimulates mTOR is currently unknown. Therefore, the purpose of this study was to compare the effects of various PA precursors and phospholipids on their ability to stimulate mTOR signaling and its ability to augment resistance training-induced changes in body composition and performance.
In phase one, C2C12 myoblasts cells were stimulated with different phospholipids and phospholipid precursors derived from soy and egg sources. The ratio of phosphorylated p70 (P-p70-389) to total p70 was then used as readout for mTOR signaling. In phase two, resistance trained subjects (n = 28, 21 ± 3 years, 77 ± 4 kg, 176 ± 9 cm) consumed either 750 mg PA daily or placebo and each took part in an 8 week periodized resistance training program.
In phase one, soy-phosphatidylserine, soy-Lyso-PA, egg-PA, and soy-PA stimulated mTOR signaling, and the effects of soy-PA (+636%) were significantly greater than egg-PA (+221%). In phase two, PA significantly increased lean body mass (+2.4 kg), cross sectional area (+1.0 cm), and leg press strength (+51.9 kg) over placebo.
PA significantly activates mTOR and significantly improved responses in skeletal muscle hypertrophy, lean body mass, and maximal strength to resistance exercise.
脂质信使磷脂酸（PA）在刺激 mTOR 信号中起着关键作用。然而，PA 刺激 mTOR 的机制目前尚不清楚。因此，本研究的目的是比较不同 PA 前体和磷脂对其刺激 mTOR 信号的能力及其增强抗阻训练引起的身体成分和性能变化的能力。
在第一阶段，用不同的磷脂和来源于大豆和鸡蛋的磷脂前体刺激 C2C12 成肌细胞。然后，用磷酸化 p70（P-p70-389）与总 p70 的比值作为 mTOR 信号的读数。在第二阶段，接受抗阻训练的受试者（n=28，21±3 岁，77±4kg，176±9cm）每天服用 750mgPA 或安慰剂，并参与 8 周的周期性抗阻训练计划。
在第一阶段，大豆磷脂酰丝氨酸、大豆溶血磷脂酸、鸡蛋 PA 和大豆 PA 刺激了 mTOR 信号，大豆 PA（+636%）的效果明显大于鸡蛋 PA（+221%）。在第二阶段，PA 显著增加了瘦体重（+2.4kg）、横截面积（+1.0cm）和腿举力量（+51.9kg），优于安慰剂。
PA 显著激活了 mTOR，显著改善了抗阻训练引起的骨骼肌肥大、瘦体重和最大力量的反应。
