Muscle Protein Synthesis, Protein Metabolism
Conditions
Keywords
Protein, Amino Acids, Anabolic Signaling, Muscle Mass
Brief summary
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.
Interventions
DIETARY_SUPPLEMENTMilk 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.
Sponsors
University of Illinois at Urbana-Champaign
Study design
Allocation
NA
Intervention model
SINGLE_GROUP
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
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).
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Fractional synthesis rates of myofibrillar protein | 8 hours | 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. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Phosphorylation of muscle anabolic signaling | 8 hours | 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. |
| Exogenous rate of phenylalanine appearance | 5 hours | 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 |
Countries
United States
Outcome results
None listed