Development of Oral Amino Acid Tracers to Study Protein Turnover in Humans
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 22
- 试验地点
- 2
- 主要终点
- Myofibrillar protein synthesis rates
研究概览
简要总结
Previous studies have used a combination of oral L-[1-13C]leucine and intravenous labeled L-[5,5,5-2H3]leucine to assess the acute postprandial changes in whole-body protein turnover (12, 19). Intravenous and dietary-labeled amino acid tracers have also been used in tandem to assess rates of myofibrillar protein synthesis in response to bolus protein ingestion and resistance exercise (46). By validating whole-body net balance to myofibrillar protein synthesis, our proposed multi-tracer approach will develop minimally invasive models to study protein turnover in a variety of populations in which traditional infusions and/or repeated blood samples are not possible (i.e. pediatric, free-living populations).
详细描述
The primary objective of the proposed study is to validate the use of a novel oral tracer model to accurately and reliably measure myofibrillar protein synthesis. It is hypothesized that oral L-[1-13C]leucine and L-[ring-2H5]phenylalanine, ingested as a bolus to mimic an intravenous 'pulse dose' administration (51, 65), will reveal similar rates of myofibrillar protein synthesis when compared to traditional intravenous L-[5,5,5-2H3]leucine infusion. Moreover, it is hypothesized that both methods will reveal the expected graded changes in myofibrillar protein synthesis in response to feeding and resistance exercise (i.e. fasted<feeding<exercise & feeding).
The secondary objective of the proposed study is to develop and validate non-invasive models to measure whole-body amino acid oxidation and net balance in response to feeding and resistance exercise. It is hypothesized that whole-body net balance, as determined by a novel oral tracer model (i.e. L-[1-13C]leucine) , will align with traditional intravenous tracer methodology (i.e. L-[5,5,5-2H3]leucine) and reveal the expected physiological changes in whole-body protein turnover in response to feeding and resistance exercise (i.e. fasted<feeding<exercise & feeding).
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Treatment
- 盲法
- None
入排标准
- 年龄范围
- 18 Years 至 35 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •Currently performing structured physical activity 2-5 days per week
排除标准
- •Unable to safely perform exercise as per PARQ+ guidelines
- •Currently using tobacco products
- •Currently using or have history of anabolic steroid use
- •Diagnosed with medical condition including type 2 diabetes, cancer, heart disease
- •Unable to abstain from supplement use (HMB, branched chain amino acids, phosphatidic acid) for at least three weeks prior to trial
- •currently using medications known to affect protein metabolism e.g. corticosteroids, NSAID, prescription-strength acne medication
- •allergic to local anesthetics
- •female: Hormonal fluctuations associated with the menstrual cycle have been reported to alter protein metabolism during exercise and may influence indices of the post-exercise myofibrillar protein synthetic response. Accordingly, the study will include males to ensure a stable hormonal environment and to increase the homogeneity of the physiological response.
结局指标
主要结局
Myofibrillar protein synthesis rates
时间窗: 5 hours
Myofibrillar protein synthesis rates assessed by oral and intravenous tracers during Fast, Fed, and Ex-Fed
次要结局
- Muscle anabolic signalling(2 and 5 hours)
- Whole-body protein turnover(5 hours)
- Amino acid oxidation and net protein balance(5 hours)
- Amino acid transporter expression(2 and 5 hours)
研究者
Daniel Moore
Associate Professor
University of Toronto