Leucine co-ingestion improves post-prandial muscle protein accretion in elderly men

详细信息    查看全文

• 作者：Benjamin T. Wall ; Henrike M. Hamer ; Anneke de Lange ; Alexandra Kiskini ; Bart B.L. Groen ; Joan M.G. Senden ; Annemie P. Gijsen ; Lex B. Verdijk ; Luc J.C. van Loon ; ^{l.vanloon@maastrichtuniversity.nl}
• 关键词：Skeletal muscle ; Aging ; Sarcopenia ; Amino acids ; Anabolic resistance
• 刊名：Clinical Nutrition
• 出版年：2013
• 出版时间：June, 2013
• 年：2013
• 卷：32
• 期：3
• 页码：412-419
• 全文大小：313 K

文摘

| Figures/TablesFigures/Tables | ReferencesReferences

Summary

Background & aims

It has been speculated that the amount of leucine in a meal largely determines the post-prandial muscle protein synthetic response to food intake. The present study investigates the impact of leucine co-ingestion on subsequent post-prandial muscle protein accretion following the ingestion of a single bolus of dietary protein in elderly males.

Methods

Twenty-four elderly men (74.3 ¡À 1.0 y) were randomly assigned to ingest 20 g intrinsically l-[1-¹³C]phenylalanine-labeled casein protein with (PRO + LEU) or without (PRO) 2.5 g crystalline leucine. Ingestion of specifically produced intrinsically labeled protein allowed us to create a plasma phenylalanine enrichment pattern similar to the absorption pattern of phenylalanine from the ingested protein and assess the subsequent post-prandial incorporation of l-[1-¹³C] phenylalanine into muscle protein.

Results

Plasma amino acid concentrations increased rapidly following protein ingestion in both groups, with higher leucine concentrations observed in the PRO + LEU compared with the PRO group (P < 0.01). Plasma l-[1-¹³C]phenylalanine enrichments increased rapidly and to a similar extent in both groups following protein ingestion. Muscle protein-bound l-[1-¹³C]phenylalanine enrichments were significantly greater after PRO + LEU when compared with PRO at 2 h (72 % ; 0.0078 ¡À 0.0010 vs. 0.0046 ¡À 0.00100 MPE, respectively; P < 0.05) and 6 h (25 % ; 0.0232 ¡À 0.0015 vs. 0.0185 ¡À 0.0010 MPE, respectively; P < 0.05) following protein ingestion. The latter translated into a greater muscle protein synthetic rate following PRO + LEU compared with PRO over the entire 6 h post-prandial period (22 % ; 0.049 ¡À 0.003 vs. 0.040 ¡À 0.003 %  h^?1, respectively; P < 0.05).

Conclusion

Leucine co-ingestion with a bolus of pure dietary protein further stimulates post-prandial muscle protein synthesis rates in elderly men.