消耗0.10-0.14g必需氨基酸(EAA)/kg/剂量(0.25-0.30g蛋白质/kg/剂量)在能量平衡期间最大程度地刺激肌肉蛋白质合成(MPS)。消耗超过该量的EAA是否会增强能量不足后的MPS和全身合成代谢尚不清楚。这项研究的目的是确定标准和高EAA摄入对能量不足后混合MPS和全身蛋白质周转的影响。
19名男性(平均值±SD;23±5y;25.4±2.7kg/m2)完成了随机分组,由两个组成的双盲交叉研究,5-d能量不足(总能量需求的-30±4%),由14-d分开。在每次能源短缺之后,混合MPS和全身蛋白质合成(PS),击穿(PB),和净平衡(NET)在休息和阻力后运动(RE)时使用灌注,恒定L-[2H5]-苯丙氨酸和L-[2H2]-酪氨酸输注。提供标准饮料(0.1g/kg,7.87±0.87g)或高(0.3g/kg,23.5±2.54g)EAA在RE后消耗。测量循环EAA。
静息时吸收后混合MPS(%/h)在治疗之间没有差异(P=0.67)。独立于EAA,餐后混合MPS在休息时(标准EAA,0.055±0.01;高EAA,0.061±0.02)和后RE(标准EAA,0.055±0.01;高EAA,在休息时,0.065±0.02)大于吸收后混合MPS(分别为P=0.02和P=0.01)。(Δ吸收后)全身(g/180分钟)PS和PB的变化高于标准EAA[平均治疗差异(95%CI),3.4(2.3,4.4);P=0.001和-15.6(-17.8,-13.5);P=0.001,分别]。NET高于标准EAA[19.0(17.3,20.7);P=0.001]。EAA浓度高于标准EAA(P=0.001)。
这些数据表明,与标准EAA摄入相比,高摄入会增强饲喂不足时的全身蛋白质状态。然而,在能量不足期间,消耗高EAA和标准EAA对混合MPS的影响是相同的。
NCT03372928,https://clinicaltrials.gov.
Consuming 0.10-0.14 g essential amino acids (EAA)/kg/dose (0.25-0.30 g protein/kg/dose) maximally stimulates muscle protein synthesis (MPS) during energy balance. Whether consuming EAA beyond that amount enhances MPS and whole-body anabolism following energy deficit is unknown. The aims of this
study were to determine the effects of standard and high EAA ingestion on mixed MPS and whole-body protein turnover following energy deficit.
Nineteen males (mean ± SD; 23 ± 5 y; 25.4 ± 2.7 kg/m2) completed a randomized, double-blind crossover
study consisting of two, 5-d energy deficits (-30 ± 4% of total energy requirements), separated by 14-d. Following each energy deficit, mixed MPS and whole-body protein synthesis (PS), breakdown (PB), and net balance (NET) were determined at rest and post-resistance exercise (RE) using primed, constant L-[2H5]-phenylalanine and L-[2H2]-tyrosine infusions. Beverages providing standard (0.1 g/kg, 7.87 ± 0.87 g) or high (0.3 g/kg, 23.5 ± 2.54 g) EAA were consumed post-RE. Circulating EAA were measured.
Postabsorptive mixed MPS (%/h) at rest was not different (P = 0.67) between treatments. Independent of EAA, postprandial mixed MPS at rest (standard EAA, 0.055 ± 0.01; high EAA, 0.061 ± 0.02) and post-RE (standard EAA, 0.055 ± 0.01; high EAA, 0.065 ± 0.02) were greater than postabsorptive mixed MPS at rest (P = 0.02 and P = 0.01, respectively). Change in (Δ postabsorptive) whole-body (g/180 min) PS and PB was greater for high than standard EAA [mean treatment difference (95% CI), 3.4 (2.3, 4.4); P = 0.001 and -15.6 (-17.8, -13.5); P = 0.001, respectively]. NET was more positive for high than standard EAA [19.0 (17.3, 20.7); P = 0.001]. EAA concentrations were greater in high than standard EAA (P = 0.001).
These data demonstrate that high compared to standard EAA ingestion enhances whole-body protein status during underfeeding. However, the effects of consuming high and standard EAA on mixed MPS are the same during energy deficit.
NCT03372928, https://clinicaltrials.gov.