Anabolic sensitivity of postprandial muscle protein synthesis to the ingestion of a protein-dense food is reduced in overweight and obese young adults
Anabolic sensitivity of postprandial muscle protein synthesis to the ingestion of a protein-dense food is reduced in overweight and obese young adults
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DOI：
10.3945/ajcn.116.130385
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发表时间：
2016-10-01
影响因子：
7.1
通讯作者：
Burd, Nicholas A.
中科院分区：
文献类型：
--
作者：
Beals, Joseph W.;Sukiennik, Richard A.;Burd, Nicholas A.
背景：过量的体脂肪减少了高胰岛素-高氨基酸钳夹引起的肌肉蛋白质合成速率。然而，在摄入蛋白质密集的食物来源后，肌肉蛋白质合成反应在一系列身体质量指数（BMI）之间没有进行比较。目的：我们比较了肥胖、超重和健康体重成年人摄入瘦猪肉后肌原纤维蛋白合成反应和潜在的营养感应机制。设计：10个健康体重[HW; BMI（kg/m2）：22.7 +/- 0.4]，10名超重（OW; BMI：27.1 +/- 0.5）和10名肥胖（OB; BMI：35.9 +/- 1.3）成人接受预充的L-[环-C-13（6）]苯丙氨酸连续输注。在摄入170 g猪肉前后采集血液和肌肉活检样品（36克蛋白质和3克脂肪），以评估骨骼肌合成代谢信号，氨基酸转运蛋白[大中性和小中性氨基酸转运蛋白（LAT 1，SNAT 2）和CD 98]和肌原纤维蛋白合成。在基线时，OW和OB组显示哺乳动物雷帕霉素复合物靶蛋白1（mTORC 1）蛋白的相对量高于HW组。猪肉摄入增加mTORC 1磷酸化仅在HW组（P = 0.001）。各组大鼠餐后LAT 1和SNAT 2蛋白含量均升高（时间效应，P < 0.05）。两组之间的基础肌原纤维蛋白合成反应相似（P = 0.43）。然而，肌原纤维蛋白的合成反应（0-300分钟）是更大的HW组（1.6倍; P = 0.005）后，猪肉摄入比在OW和OB groups.Conclusions：有一个减少肌原纤维蛋白的合成反应的蛋白质密集的食物的摄入超重和肥胖的成年人相比，健康体重控制。这些数据表明，餐后肌原纤维蛋白合成反应受损可能是脂肪量增加的早期缺陷，可能依赖于改变的合成代谢信号，从而降低肌肉对食物摄入的敏感性。
Background: Excess body fat diminishes muscle protein synthesis rates in response to hyperinsulinemic-hyperaminoacidemic clamps. However, muscle protein synthetic responses after the ingestion of a protein-dense food source across a range of body mass indexes (BMIs) have not been compared.Objective: We compared the myofibrillar protein synthetic response and underlying nutrient-sensing mechanisms after the ingestion of lean pork between obese, overweight, and healthy-weight adults.Design: Ten healthy-weight [HW; BMI (in kg/m(2)): 22.7 +/- 0.4], 10 overweight (OW; BMI: 27.1 +/- 0.5), and 10 obese (OB; BMI: 35.9 +/- 1.3) adults received primed continuous L-[ring-C-13(6)]phenylalanine infusions. Blood and muscle biopsy samples were collected before and after the ingestion of 170 g pork (36 g protein and 3 g fat) to assess skeletal muscle anabolic signaling, amino acid transporters [large neutral and small neutral amino acid transporters (LAT1, SNAT2) and CD98], and myofibrillar protein synthesis.Results: At baseline, OW and OB groups showed greater relative amounts of mammalian target of rapamycin complex 1 (mTORC1) protein than the HW group. Pork ingestion increased mTORC1 phosphorylation only in the HW group (P = 0.001). LAT1 and SNAT2 protein content increased during the postprandial period in all groups (time effect, P < 0.05). Basal myofibrillar protein synthetic responses were similar between groups (P = 0.43). However, myofibrillar protein synthetic responses (0-300 min) were greater in the HW group (1.6-fold; P = 0.005) after pork ingestion than in the OW and OB groups.Conclusions: There is a diminished myofibrillar protein synthetic response to the ingestion of protein-dense food in overweight and obese adults compared with healthy-weight controls. These data indicate that impaired postprandial myofibrillar protein synthetic response may be an early defect with increasing fat mass, potentially dependent on altered anabolic signals, that reduces muscle sensitivity to food ingestion.