Role of Leucine in the Regulation of Human Myofibrillar Protein Synthesis at Rest and Following Resistance Exercise

NCT01492010 | Completed

• 1 other identifier: LEU-10-141
• Study Type: interventional
• Target: 24
• Locations: 1 country
• Sites: 1

Brief Summary

Muscle mass is normally maintained through the regulated balance between the processes of protein synthesis (i.e. making new muscle proteins) and protein breakdown (breaking down old muscle proteins). Proteins are composed of amino acids and we know that amino acids increase muscle protein synthesis. However, not all amino acids are the same. Essential amino acids are ones that must be consumed through food, while non-essential amino acids can be made by our body. Interestingly, the essential amino acids are all that are required to increase the rate of muscle protein synthesis. In addition, the essential amino acid leucine appears to be particularly important in regulating protein synthesis. However, how leucine is able to increase protein synthesis is not entirely understood. Previously, it has been shown that 20-25 g of high-quality protein, such as that found in milk, appears to be the amount of protein that maximizes the rate of muscle protein synthesis after performing a bout of resistance exercise. Thus, the aim is to measure the synthesis of new muscle proteins after ingesting the following:

1. 1.25g whey protein
2. 2.6.25g whey protein supplemented with leucine
3. 3.6.25g whey protein supplemented with essential amino acids but no leucine

Conditions

Regulation of Muscle Protein Synthesis

Keywords

skeletal muscle; FSR; resistance exercise; leucine; protein

Outcome Measures

Primary Outcomes (1)

• Muscle protein synthesis

  Muscle protein synthesis will be expressed as fractional synthetic rate (FSR) by dividing the increment in enrichment in the product, i.e. protein-bound C13phe, by the enrichment of the precursor (= intracellular availability).

  5 hours postprandial

Secondary Outcomes (1)

• Signaling molecule phosphorylation status

  1, 3, and 5 hours

Study Arms (3)

25 g protein

EXPERIMENTAL

25 g whey protein

Dietary Supplement: whey protein

6.25 g protein supplemented with leucine

EXPERIMENTAL

6.25 g protein supplemented with leucine

Dietary Supplement: whey protein supplemented with leucine

6.25 g whey protein with EAA

EXPERIMENTAL

6.25 g protein supplemented with a mixture of essential amino acids devoid of leucine

Dietary Supplement: whey protein supplemented with essential amino acids

Interventions

whey protein DIETARY_SUPPLEMENT

25 g whey protein

Also known as: whey protein powder

25 g protein

whey protein supplemented with leucine DIETARY_SUPPLEMENT

6.25 g whey protein supplemented with free form leucine

Also known as: whey protein powder supplemented with free-form leucine

6.25 g protein supplemented with leucine

whey protein supplemented with essential amino acids DIETARY_SUPPLEMENT

6.25 g whey protein supplemented with essential amino acids devoid of leucine

Also known as: whey protein supplemented with EAA devoid of leucine

6.25 g whey protein with EAA

Eligibility Criteria

• Age: 18 Years - 35 Years
• Sex: male
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• male
• years of age
• non-smoker/ non-tobacco product user

You may not qualify if:

• heart disease
• vascular disease
• rheumatoid arthritis
• diabetes
• poor lung function
• uncontrolled blood pressure
• dizziness
• thyroid problems

Sponsors & Collaborators

• McMaster University: lead
• University of California, Davis: collaborator
• Canadian Institutes of Health Research (CIHR): collaborator
• Natural Sciences and Engineering Research Council, Canada: collaborator

Study Sites (1)

Exercise Metabolism Research Laboratory, McMaster Univeristy

Hamilton, Ontario, L8S 4K1, Canada

Location

Related Publications (1)

• Churchward-Venne TA, Burd NA, Mitchell CJ, West DW, Philp A, Marcotte GR, Baker SK, Baar K, Phillips SM. Supplementation of a suboptimal protein dose with leucine or essential amino acids: effects on myofibrillar protein synthesis at rest and following resistance exercise in men. J Physiol. 2012 Jun 1;590(11):2751-65. doi: 10.1113/jphysiol.2012.228833. Epub 2012 Mar 25.

  PMID: 22451437 DERIVED

MeSH Terms

Interventions

Whey Proteins; Leucine; Amino Acids, Essential

Intervention Hierarchy (Ancestors)

Milk Proteins; Animal Proteins, Dietary; Dietary Proteins; Proteins; Amino Acids, Peptides, and Proteins; Whey; Milk; Dairy Products; Food; Diet, Food, and Nutrition; Physiological Phenomena; Food and Beverages; Amino Acids, Branched-Chain; Amino Acids

Study Officials

• Stuart M Phillips, PhD

  McMaster University

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principal Investigator

Study Record Dates

• First Submitted: December 12, 2011
• First Posted: December 14, 2011
• Study Start: June 1, 2010
• Primary Completion: August 1, 2010
• Study Completion: September 1, 2010
• Last Updated: February 24, 2020

Record last verified: 2020-02

Locations

CA (1)