Time Course of Postprandial Protein Metabolism

Time-dependent Regulation of Postprandial Muscle Protein Synthesis After Milk Protein Ingestion in Young Men

The anabolic action of 'fast' whey protein on the regulation of postprandial muscle protein synthesis has been established to be short-lived in healthy young adults. Our aim was assess the time course of anabolic signaling events and stimulation of muscle protein synthesis rates (MPS) after ingestion of a food source that represents a more typical meal-induced pattern of aminoacidemia, namely milk protein concentrate, in healthy young males.

Study Overview

• Status: Completed
• Conditions: Muscle Protein Synthesis; Protein Metabolism
• Intervention / Treatment: Dietary supplement: Milk Protein Concentrate

• Study Type: Interventional
• Enrollment (Actual): 7
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Illinois
    • Urbana, Illinois, United States, 61801
      • Freer Hall

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion criteria

• Males
• Aged between 18-35 years
• Healthy, recreationally active
• BMI < 30 kg/m2

Exclusion criteria

• Smoking
• Allergies to milk proteins
• Vegetarians
• Diagnosed GI tract diseases
• Female
• Arthritic conditions
• A history of neuromuscular problems
• Previous participation in amino acid tracer studies
• Predisposition to hypertrophic scarring or keloid formation
• Individuals on any medications known to affect protein metabolism (i.e. corticosteroids, non-steroidal anti-inflammatories, or prescription strength acne medications).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: BASIC_SCIENCE
• Allocation: NA
• Interventional Model: SINGLE_GROUP
• Masking: NONE

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

EXPERIMENTAL: Milk Protein Concentrate; Seven young men (age: 22±1 y) will undergo repeated blood and biopsy sampling during primed continuous L-[ring-2H5]phenylalanine and L-[1-13C]leucine tracer infusions, and ingested 38 g of L-[1-13C]phenylalanine- and L-[1-13C]leucine-labeled milk protein concentrate

Dietary supplement: Milk Protein Concentrate; The macronutrient composition and energy of the milk protein beverage provided to participants is 38 g protein (3.46 g leucine), 4.17 g carbohydrate, and 1.4 g fat. The milk protein met all chemical and bacteriologic specifications for human consumption. The L-[1-13C]phenylalanine and L-[1-13C]leucine enrichments in the milk protein concentrate averaged 38.3 and 10.8 mole percent excess (MPE), respectively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fractional synthesis rates of myofibrillar protein	Myofibrillar protein synthesis rates will be assessed during the postabsorptive period for 3 hours, and every 1-2 hours during the 5 hours after protein ingestion. This will allow us assess the timecourse of muscle protein synthesis after eating.	8 hours

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Phosphorylation of muscle anabolic signaling	Phosphorylation of anabolic signaling pathways (mTORC1, AKT, and P70S6K) involved in the stimulation of myofibrillar protein synthesis rates will be assessed during the postabsorptive period for 3 hours, and every 1-2 hours during the 5 hours after protein ingestion.	8 hours
Exogenous rate of phenylalanine appearance	Dietary derived phenylalanine availability will be measured during the 5 h postprandial phase to determine its relationship with the fractional synthesis rates of myofibrillar protein and phosphorylation of muscle anabolic signaling	5 hours

Collaborators and Investigators

• Sponsor: University of Illinois at Urbana-Champaign

Study record dates

Study Major Dates

• Study Start (ACTUAL): October 1, 2014
• Primary Completion (ACTUAL): November 1, 2014
• Study Completion (ACTUAL): August 26, 2019

Study Registration Dates

• First Submitted: September 3, 2019
• First Submitted That Met QC Criteria: October 7, 2019
• First Posted (ACTUAL): October 10, 2019

Study Record Updates

• Last Update Posted (ACTUAL): October 10, 2019
• Last Update Submitted That Met QC Criteria: October 7, 2019
• Last Verified: August 1, 2019

More Information

Terms related to this study

• Keywords: Protein; Muscle Mass; Amino Acids; Anabolic Signaling
• Additional Relevant MeSH Terms: Molecular Mechanisms of Pharmacological Action; Chelating Agents; Sequestering Agents; Caseins
• Other Study ID Numbers: 14234

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No