Proline Metabolism in Severely Burned Patients: Effect of Modulated Parenteral Feeding
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|ClinicalTrials.gov Identifier: NCT00216983|
Recruitment Status : Withdrawn (State of Mass. tightened regulations for making intravenous solutions for research subjects. Study was withdrawn and no participants were enrolled.)
First Posted : September 22, 2005
Last Update Posted : January 13, 2017
|Condition or disease|
Proline is a non-essential amino acid. Its synthesis and catabolism is via the pathway of ornithine and glutamate, the latter two amino acids serve as its immediate precursors as well as metabolites. Ornithine is one of the intermediates for urea cycle, and glutamate is metabolically connected to tricarboxylic acid (TCA) cycle, the major cycle for energy production.
It is hypothesized that the significantly increased rates of net nitrogen loss and energy "production", as the consequence of the accelerated activities of both the urea and TCA cycles in burn injury "drain" both ornithine and glutamate, thus depleting tissues of the availability of proline. Hence, the de novo synthesis of proline is likely to be affected by the reduced availability of its major precursors: glutamate and ornithine.
This hypothesis is supported by 1) tissue and circulating glutamine content are reduced in stressed conditions; 2) ornithine disposal via oxidation is significantly increased after burn injury(2). Therefore, the availability of proline is likely to be limiting after burn injury for the synthesis of proteins. On the other hand, proline requirement is significantly increased in burn patients due to the high demand for tissue repair and wound healing. As a result, providing an adequate proportion of its precursors, glutamine / glutamate and / or as preformed proline, is of importance to maintain the appropriate supply and balance of amino acids for protein and other synthetic functions after burn injury.
The overall purpose of the study is to evaluate the effect of depleting proline supply in the nutritional support regimen on proline metabolism in the burn patients, this includes the rate of proline oxidation after burn injury, the rate of proline de novo synthesis from its immediate precursors glutamate and ornithine. The specific aims of the proposed study are: 1) to determine the kinetic status of proline metabolism and whole body proline balance under the following nutritional states: (a) "fasting; (b) regular total parenteral nutrition (TPN); (c)TPN with isonitrogenous depletion of proline, glutamate and ornithine metabolism under nutritional conditions studied in specific aim 1) above.
|Study Type :||Observational|
|Actual Enrollment :||0 participants|
|Official Title:||Proline Metabolism in Severely Burned Patients: Effect of Modulated Parenteral Feeding.|
|Study Start Date :||September 1997|
|Estimated Primary Completion Date :||January 2010|
|Estimated Study Completion Date :||January 2010|
Fasting condition to measure:
We will study the quantitative relationships among proline, ornithine and glutamate with an emphasis on evaluating the rate of proline disposal and its conversion to ornithine and glutamate in burn patients. When the patients are receiving regular TPN or TPN depleted with proline - arginine - glutamate.
We wull evaluate the rate of proline de novo synthesis from glutamate or ornithine in burn patients when the patients are receiving regular TPN or TPN depleted proline-arginine-glutamate.
- This is a study for measuring the protein kinetics for metabolism of the amino acid proline kinetics will be derived from measurements on blood and air samples taken as part of the study. [ Time Frame: 12 hours ]
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT00216983
|United States, Massachusetts|
|Massachusetts General Hospital Burn Unit|
|Boston, Massachusetts, United States, 02114|
|Principal Investigator:||Ronald G Tompkins, MD, ScD||MGH, Shriners Burn Hospital - Boston|