Arginine Synthesis in Healthy Adult Humans

Study Overview
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Brief Summary
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Arginine synthesis in mammals is a complex process involving at least 8 enzymes and intracellular and interorgan transfer of substrates. The investigators have shown in our neonatal studies that there is no conversion of glutamate to arginine but proline label appears in ornithine, citrulline and arginine. It is clear therefore that arginine is synthesized in human neonates from proline. In adults the source of the carbon backbone is less clear.

Detailed Description
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Through a series of test in healthy adults using tandem mass spectrometry with carbon labeled GLN and nitrogen labeled PRO to determine the dietary source for the carbon chain of ORN, CIT and ARG. Additionally, using Nitrogen labeled GLN, we will identify the source of the nitrogen atoms in these amino acids. Using guanidino - 15N2 arginine, 1-13C Glutamine, 2-15N Glutamine and 15N Proline we will be able to: determine the flux of arginine and proline in healthy adult volunteers determine and compare the flux of carbon and nitrogen labeled glutamine demonstrate whether glutamine or proline provides the carbon backbone for ornithine, citrulline and arginine in adults. the source of the N atoms in ornithine, citrulline and arginine.

Official Title
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Arginine Synthesis in Healthy Adult Humans: Does Proline or Glutamate Provide the 5-Carbon Chain?

Conditions
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Healthy

Intervention / Treatment
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* Other: 2-15N glutamine
* Other: 15N2 arginine and 15N proline
* Other: 1-13C glutamine


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: 5 men of average weight 80 kg will be studied healthy, with no know disease of liver, and/or kidney weight stable Exclusion Criteria: weith loss or gain over the last three months on medications known to affect amino acid metabolism known liver, kidney disease condition

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 55 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: Diagnostic
Allocation: Randomized
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Active Comparator: Test Study 1: 2-15N glutamine<br>To determine the contributions make by glutamine to the provision of nitrogen for ornithine, citrulline and arginine syntesis in adults. | Other: 2-15N glutamine<br>* Glutamine with N15 isotope tracer<br>|
| Active Comparator: Test Study 2: 15N2 arginine &15N proline<br>administration of 15N2 arginine &15N proline to measure arginine and proline flux | Other: 15N2 arginine and 15N proline<br>* Arginine and Proline isotope tracers<br>|
| Active Comparator: Study Test 3: 1-13C glutamine<br>to determine to contribution of glutamine to the carbon skeleton of ornithine, citrulline and arginine in adults. | Other: 1-13C glutamine<br>* Glutamine carbon isotope tracer<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Blood Isotope Levels |  | 8 hours | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Arginine synthesis, 15N2 arginine, 1-13C Glutamine, 2-15N Glutamine, 15N Proline