Metabolic fate of a large amount of 13C-glycerol ingested during prolonged exercise
| Autor: | Carole Lavoie, Martin Milot, A. Scotto, Denis Massicotte, F. Péronnet, H. M’Kaouar |
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| Rok vydání: | 2005 |
| Předmět: |
Blood Glucose
Glycerol Male medicine.medical_specialty Time Factors Physiology Radioimmunoassay Calorimetry Protein oxidation chemistry.chemical_compound Oxygen Consumption Physiology (medical) Internal medicine medicine Humans Insulin Urea Ingestion Orthopedics and Sports Medicine Lactic Acid Food science Exercise Carbon Isotopes Chemistry Respiration Fatty Acids Public Health Environmental and Occupational Health Substrate (chemistry) Calorimetry Indirect General Medicine Metabolism Carbon Dioxide Carbohydrate Endocrinology Gluconeogenesis Spectrophotometry Oxidation-Reduction |
| Zdroj: | European Journal of Applied Physiology. 96:322-329 |
| ISSN: | 1439-6327 1439-6319 |
| Popis: | We have shown that the oxidation rate of exogenous glycerol and glucose during prolonged exercise were similar when ingested in small amounts (0.36 g/kg) (J Appl Physiol 90:1685,2001). The oxidation rate of exogenous carbohydrate increases with the amount ingested. We, thus, hypothesized that the oxidation rate of exogenous glycerol would also be larger when ingested in large amount. The study was conducted on six male subjects exercising for 120 min at 64 (2)%VO2max while ingesting 1 g/kg of 13C-glycerol. Substrate oxidation was measured using indirect respiratory calorimetry corrected for protein oxidation, and from V 13CO2 at the mouth. The 13C enrichment of plasma glucose was also measured in order to follow the possible conversion of 13C-glycerol into glucose. In spite of the large amount of glycerol ingested and absorbed (plasma glycerol concentration = 8.0 (0.3) mmol/l at min 100), exogenous glycerol oxidation over the last 80 min of exercise [8.8 (1.6) g providing 4.1 (0.7)% of the energy yield] was similar to that observed when 0.36 g/kg was ingested. The comparison between the 13C enrichment of plasma glucose and the oxidation rate of 13C-glycerol showed that a portion of exogenous glycerol was converted into glucose before being oxidized, but also suggested that another portion could have been directly oxidized in peripheral tissues. |
| Databáze: | OpenAIRE |
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