13C nuclear magnetic resonance study of glycogen resynthesis in muscle after glycogen-depleting exercise in healthy men receiving an infusion of lipid emulsion.
In healthy individuals, glycogen recovery after a strong depletion is known to be rapid and insulin independent during the initial phase, and subsequently, slow and insulin dependent. Free fatty acids (FFAs) as a putative source of insulin resistance (IR) could thus impair glycogen recovery during the second period. Using in vivo 13C nuclear magnetic resonance (NMR), we studied the effect of long-chain triglyceride emulsion on gastrocnemius glycogen resynthesis during a 3-h recovery period after 90 min of moderate exercise consisting of plantar flexion on overnight-fasted healthy men (n = 8). In separate experiments, each subject was infused with 10% Ivelip (0.015 ml x kg(-1) x min(-1)) or 10% glycerol (0.13 mg x kg(-1) x min(-1)). NMR spectra were acquired before and at the end of the exercise and during the recovery period. Whole-body glucose and lipid oxidation rates (indirect calorimetry), plasma insulin, C-peptide, glucose, lactate, beta-hydroxybutyrate, triglycerides, and FFAs were determined. Glycogen consumption was 47.6 +/- 4.5% (glycerol) and 49.7 +/- 4.8% (Ivelip) of the initial glycogen. An acquired IR in the Ivelip group was significant at the onset of the recovery period by homeostasis model assessment (P = 0.002). Glycogen resynthesis in the glycerol group appeared faster during the 1st h than during the subsequent 2nd h of the postexercise period. The glycogen resynthesis level was significantly lower in the Ivelip group than in the glycerol group during the recovery period (P = 0.04 during the 1st h and P = 0.001 during the next 2 h). During the recovery, plasma lactate and whole-body oxidation rates were similar in the two groups, whereas glycemia was significantly higher in the Ivelip group. A decreased cellular uptake of glucose as a substrate for glycogenosynthesis, rather than a competition between oxidation of carbohydrate and FFA, is discussed.
Delmas-Beauvieux
M C
MC
Résonance Magnétique des Systèmes Biologiques, Unité Mixte de Recherche 5536, Centre National de la Recherche Scientifique-Université Victor Segalen Bordeaux 2, France. cath@rmsb.u-bordeaux2.fr
Quesson
B
B
Thiaudière
E
E
Gallis
J L
JL
Canioni
P
P
Gin
H
H
D000328:Adult; D002247:Carbon Isotopes; D004655:Emulsions; D015444:Exercise / Q000502:physiology*; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005990:Glycerol / Q000097:blood / Q000494:pharmacology; D006003:Glycogen / Q000037:antagonists & inhibitors* / Q000096:biosynthesis*; D006801:Humans; D007262:Infusions, Intravenous; D007333:Insulin Resistance / Q000502:physiology; D050356:Lipid Metabolism; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D018482:Muscle, Skeletal / Q000187:drug effects* / Q000378:metabolism*; D010084:Oxidation-Reduction; D012016:Reference Values; D014280:Triglycerides / Q000097:blood / Q000494:pharmacology*
D002247:Carbon Isotopes; D004655:Emulsions; D005230:Fatty Acids, Nonesterified; D014280:Triglycerides; D006003:Glycogen; D005990:Glycerol