REDUCING EARLY ATROPHY WITH LEUCINE DURING IMMOBILIZATION OF SKELETAL MUSCLE

Completed

Conditions: Muscle Protein Turover
Muscle Protein Synthesis and Breakdown
10037008
10028302

Registration Number: NL-OMON45771

Lead Sponsor: Maastricht University

Brief Summary: Not available

Detailed Description: Not available

Recruitment & Eligibility

Status: Completed

Sex: Not specified

Target Recruitment: 64

Inclusion Criteria

* Moderately active
* Male or female age 18-35 or 60-80 years of age inclusive
* BMI not lower than 18.5 and not higher than 30 kg/m2
* Having given informed consent

Exclusion Criteria

* Previous participation in a 13C amino acid tracer study (within the last 5 years)
* Lower limb and/or back injuries
* A history of thrombosis/cardiovascular disease
* Use of anticoagulants
* Musculoskeletal/orthopedic disorders
* Structured resistance exercise training
* Use of corticosteroids
* Current use of protein supplements (during the study)
* Diabetes (type I or II)
* Pregnancy
* Hormone replacement therapy
* Third generation oral contraceptives
* Use of tobacco products

Study & Design

Study Type: Interventional

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>Main study parameter/endpoint<br /><br>The main study endpoint is cumulative FSR as a measure of muscle protein<br /><br>synthesis rates (MPS) based on the oral tracer deuterium oxide. In order to<br /><br>determine cumulative FSR, the following parameters will be measured via<br /><br>GC-C-IRMS and GCMS respectively:<br /><br>* Muscle protein-bound L-[2,3,3,3-2H4]-alanine enrichment (expressed as MPE)<br /><br>* Plasma free L-[2,3,3,3-2H4]-alanine enrichment (expressed as MPE)<br /><br>* Saliva 2H2O enrichment (Expressed as APE)</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>Secondary study parameters/endpoints<br /><br>Secondary endpoints include:<br /><br>* Quadriceps whole-muscle CSA as assessed via CT scan.<br /><br>* Plasma, muscle free, and muscle protein-bound L-[ring-13C6]-phenylalanine<br /><br>enrichment.<br /><br>* Fractional breakdown rates (FBR) of muscle protein based on 3,3-D2<br /><br>phenylalanine tracer dilution in plasma and muscle.<br /><br>* Fractional synthesis rates (FSR) of muscle protein based on<br /><br>L-[ring-13C6]-phenylalanine tracer incorporation into bound muscle protein.<br /><br>* Activation of signaling molecules regulating muscle protein synthesis and<br /><br>breakdown (specified in 8.3.6.5) will be established via Western blots.<br /><br>Quantitative Real-Time PCR Analysis of MAFbx/Atrogin-1, MuRF1, FoxO and<br /><br>Ubiquitin Expression will also be performed.</p><br>