Nutritional and Contractile Regulation of Muscle Growth
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| First Received Date ICMJE | April 29, 2009 | ||||||||
| Last Updated Date | May 3, 2012 | ||||||||
| Start Date ICMJE | April 2009 | ||||||||
| Estimated Primary Completion Date | September 2013 (final data collection date for primary outcome measure) | ||||||||
| Current Primary Outcome Measures ICMJE |
Muscle protein synthesis [ Time Frame: Measured during the 8-hour infusion study ] [ Designated as safety issue: No ] | ||||||||
| Original Primary Outcome Measures ICMJE | Same as current | ||||||||
| Change History | Complete list of historical versions of study NCT00891696 on ClinicalTrials.gov Archive Site | ||||||||
| Current Secondary Outcome Measures ICMJE |
Phosphorylation status of mTOR signaling proteins [ Time Frame: Measured during the 8-hour infusion study ] [ Designated as safety issue: No ] | ||||||||
| Original Secondary Outcome Measures ICMJE | Same as current | ||||||||
| Current Other Outcome Measures ICMJE | Not Provided | ||||||||
| Original Other Outcome Measures ICMJE | Not Provided | ||||||||
| Descriptive Information | |||||||||
| Brief Title ICMJE | Nutritional and Contractile Regulation of Muscle Growth | ||||||||
| Official Title ICMJE | Nutritional and Contractile Regulation of Muscle Growth (Cycle 2) | ||||||||
| Brief Summary | Muscle wasting, which involves the loss of muscle tissue, is common in many conditions, such as cancer, AIDS, trauma, kidney failure, bone fracture, and sepsis. It is also prevalent among the elderly and in people who experience periods of physical inactivity and weightlessness. Muscle wasting can lead to overall weakness, immobility, physical dependence, and a greater risk of death when exposed to infection, surgery, or trauma. There is a need to develop scientifically based treatments that prevent muscle wasting. As one step towards such a goal, this study will examine the physiological and cellular mechanisms that regulate skeletal muscle growth. |
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| Detailed Description | Skeletal muscle comprises about 40% of one's body weight and contains about 50% to 75% of all the proteins in the human body. The turnover of protein is a regular process in the human body. In healthy adults, the interplay between muscle protein synthesis and muscle protein breakdown results in no net growth or loss of muscle mass. But when the scale tips towards muscle protein breakdown, muscle wasting can occur. This can result in negative consequences, because not only does muscle fill the obvious role of converting chemical energy into mechanical energy for moving and maintaining posture, but muscle is also involved in the following less apparent roles: regulating metabolism; removing potentially toxic substances from blood circulation; producing fuel for other tissues; storing energy and nitrogen, both of which are important for fueling the brain and immune system; and facilitating wound healing during malnutrition, starvation, injury, and disease. Therefore, muscle is important not only for physical independence but also for mere survival of the human body. In fact, a mere 30% loss of the body's proteins results in impaired respiration and circulation and can eventually lead to death. The purpose of this study is to examine the physiological and cellular mechanisms that regulate skeletal muscle growth. Results from the study may help to develop future treatments for maintaining and possibly increasing muscle mass as a way to improve function, reduce disease complications, and increase survival. This study will enroll healthy participants who will be randomly assigned to one of several treatment arms within one of three separate experiments. Overall, the three experiments will examine the following: (1) whether the mammalian target of rapamycin (mTOR) signaling pathway--a group of molecules that work together to control a specific cellular function--is responsible for stimulating muscle protein synthesis after resistance exercise and/or ingestion of an amino acid supplement; (2) whether restricting blood flow with a blood pressure cuff during low-intensity resistance exercise ultimately leads to muscle protein synthesis; and (3) whether aging is associated with reduced physiological and cellular mechanisms that are related to muscle protein synthesis and whether such a reduction can be overcome by post-exercise ingestion of an amino acid supplement or blood flow restriction during low-intensity resistance exercise. Depending on which treatment arm participants are assigned to, they may receive amino acid supplementation, the drug rapamycin, the drug sodium nitroprusside, and/or placebo. They may also undergo high-intensity resistance exercise, low-intensity resistance exercise, or low-intensity resistance exercise along with blood flow restriction. All participants will attend a single 8-hour study visit and a follow-up visit 1 week later. During the study visit, participants will undergo the following: measurements of vital signs, height, and weight; blood and urine sampling; a dual energy x-ray absorptiometry (DEXA) scan; and an infusion study that will include additional blood sampling, muscle biopsies, and assigned interventions. The follow-up visit will include evaluation of any incisions that were made during the infusion study. |
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| Study Type ICMJE | Interventional | ||||||||
| Study Phase | Not Provided | ||||||||
| Study Design ICMJE | Allocation: Randomized Intervention Model: Factorial Assignment Masking: Double Blind (Subject, Investigator) Primary Purpose: Basic Science |
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| Condition ICMJE | Sarcopenia | ||||||||
| Intervention ICMJE |
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| Study Arm (s) |
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| Publications * |
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* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline. |
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| Recruitment Information | |||||||||
| Recruitment Status ICMJE | Recruiting | ||||||||
| Estimated Enrollment ICMJE | 144 | ||||||||
| Estimated Completion Date | September 2013 | ||||||||
| Estimated Primary Completion Date | September 2013 (final data collection date for primary outcome measure) | ||||||||
| Eligibility Criteria ICMJE | Inclusion Criteria:
Exclusion Criteria:
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| Gender | Both | ||||||||
| Ages | 18 Years to 85 Years | ||||||||
| Accepts Healthy Volunteers | Yes | ||||||||
| Contacts ICMJE |
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| Location Countries ICMJE | United States | ||||||||
| Administrative Information | |||||||||
| NCT Number ICMJE | NCT00891696 | ||||||||
| Other Study ID Numbers ICMJE | 08-306, R01AR049877 | ||||||||
| Has Data Monitoring Committee | No | ||||||||
| Responsible Party | The University of Texas, Galveston | ||||||||
| Study Sponsor ICMJE | The University of Texas, Galveston | ||||||||
| Collaborators ICMJE | National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS) | ||||||||
| Investigators ICMJE |
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| Information Provided By | The University of Texas, Galveston | ||||||||
| Verification Date | May 2012 | ||||||||
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ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP |
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