The Impact of Leg Immobilization on Postabsorptive and Postprandial Muscle Protein Breakdown in Healthy Young Males

Study Overview
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Brief Summary
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The present study will seek the quantify the simultaneous muscle protein synthesis and breakdown response with and without amino acid provision in humans following 2 days of immobilisation.

Official Title
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The Impact of Leg Immobilization on Postabsorptive and Postprandial Muscle Protein Breakdown in Healthy Young Males

Conditions
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Healthy

Intervention / Treatment
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* Other: Postabsorptive
* Other: Postprandial
* Procedure: Immobilisation


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Male 18-40 years of age Body mass index between 18.5 and 30 Exclusion Criteria: Any diagnosed metabolic impairment (e.g. type 1 or 2 Diabetes) Any diagnosed cardiovascular disease (e.g. deep vein thrombosis) or hypertension Chronic use of any prescribed or over the counter pharmaceuticals (that may modulate muscle protein metabolism) A personal or family history of epilepsy, seizures or schizophrenia Any known disorders in muscle metabolism Regular use of nutritional supplements Allergy to lidocaine Allergy to one or multiple amino acids Recent (within the last 6 months) or current musculoskeletal injury (e.g. leg fracture) as these could be exacerbated by the intervention e.g. unilateral leg immobilisation, or mean the participant is unable to use crutches. Having received or ingested a stable isotope tracer in the past

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 40 Years

Sexes Eligible for Study
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Male

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Postabsorptive<br>Saline infusion to mimic postabsorptive circulating amino acid concentrations | Other: Postabsorptive<br>* Saline will be infused to mimic postabsorptive circulating amino acid concentrations<br>Procedure: Immobilisation<br>* One leg will undergo 2 days immobilisation prior to the test day<br>|
| Active Comparator: Postprandial<br>Amino acid infusion to mimic postprandial circulating amino acid concentrations | Other: Postprandial<br>* An amino acid infusate will be administered to mimic postprandial circulating amino acid concentrations<br>Procedure: Immobilisation<br>* One leg will undergo 2 days immobilisation prior to the test day<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle protein breakdown rate | Muscle protein breakdown rate (FBR, measured in %/h) during 1 hour of saline or amino acid infusion | 1 hour | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Muscle protein breakdown rate | Muscle protein breakdown rate (FBR, measured in %/h) during 3 hours of saline or amino acid infusion | 3 hours | 
| Muscle protein synthesis rate | Muscle protein synthesis rate (FSR, measured in %/h) during 3 hours of saline or amino acid infusion measured using a D5 phenylalanine infusion | 3 hours |