Food First Approach to Stimulate Muscle Protein Synthesis in Healthy Adults
Condition: Hypertrophy
MeSH terms: Hypertrophy
Study type: Interventional

Summary: 
      In a crossover design 10 young healthy adults (20-35 y) will receive stable isotope tracer
      infusions and perform a single bout of resistance exercise. Immediately after exercise
      participants will ingest either 3.5 oz of Salmon fillet or its constituent macronutrients as
      isolated amino acids and fat. Repeated blood and breath samples as well as muscle biopsies
      will be collected to determine whole body amino acid kinetics, muscle amino acid
      transporters, anabolic signalling and myofibrillar protein synthesis rates during the trials
    

Detailed description: 
      On both infusion trials, participants will report to the laboratory at 0700 h after an
      overnight fast. Upon arrival to the lab, the participant will fill out a questionnaire and a
      baseline breath sample will be collected to determine 13CO2 enrichment by isotope ratio mass
      spectrometry. A Teflon catheter will be inserted into the antecubital vein for a baseline
      blood sample (t=-210) and then participants will receive priming doses of NaH13CO2 (2.35
      µmol·kg-1), L-[1-13C]leucine (7.6 µmol·kg-1), and L-[ring-2H5]phenylalanine (2.0 µmol·kg-1).
      Subsequently, a continuous intravenous solution of L-[1-13C]leucine (0.10 µmol·kg-1·min-1)
      and L-[ring-2H5]phenylalanine (0.05 µmol·kg-1·min-1) will be initiated (t=-210) and
      maintained over the infusion trials. A second Teflon catheter will be inserted into a heated
      dorsal vein for repeated arterialized blood sampling and remained patent by a 0.9% saline
      drip. Breath samples and arterialized blood samples will be collected every 30 to 60 minutes
      during the postabsorptive and postprandial states. In the post-absorptive state of infusion
      trial 1, muscle biopsies will be collected at t=-150 and -30 min of infusion to determine
      basal-state myofibrillar protein synthesis rates, relative skeletal muscle amino acid
      transporter content, and anabolic-related signaling. In the subsequent cross-over trial only
      1 muscle biopsy will be collected at t=-30 for Western blot analysis and postabsorptive
      myofibrillar protein-bound tracer enrichment. After collection of the resting muscle biopsy
      at t=-30 for both trials, the participants will perform resistance exercise that consists of
      4 sets of 10-12 repetitions or to muscular failure at 65-70% of 1-RM for both leg press and
      leg extension exercise.

      Immediately after the completion of the exercise bout, participants will ingest either 3.5 oz
      of Salmon fillet or a matched isolated amino acid and fat mixture (t=0). Completion of the
      meal will mark the start of the postprandial stage and additional muscle biopsies will be
      collected at t=120 and t=300.
    

Intervention name(s): Resistance exercise; Salmon; Isolated amino acids and fatty acids
Intervention type(s): Behavioral; Other; Dietary Supplement
Intervention description(s): Participants will perform leg press and leg extension immediately prior to ingestion of salmon or isolated mixture; Participants will ingest salmon immediately after resistance exercise; Participants will ingest a mixture of isolated amino acids and fatty acids immediately after resistance exercise
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: None (Open Label)
Primary purpose: Basic Science