Pierre Gachon

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The speed of absorption of dietary amino acids by the gut varies according to the type of ingested dietary protein. This could affect postprandial protein synthesis, breakdown, and deposition. To test this hypothesis, two intrinsically 13C-leucine-labeled milk proteins, casein (CAS) and whey protein (WP), of different physicochemical properties were(More)
To evaluate the importance of protein digestion rate on protein deposition, we characterized leucine kinetics after ingestion of "protein" meals of identical amino acid composition and nitrogen contents but of different digestion rates. Four groups of five or six young men received an L-[1-13C]leucine infusion and one of the following 30-g protein meals: a(More)
Whole-body and splanchnic protein metabolism were determined in six young (mean age: 22.7 y) and six old (68.2 y) men before and during a standardized meal (41.8 kJ/kg) containing 15.6% protein, by using a combination of intravenous ([13C]leucine) and oral ([2H3]leucine) tracers. In the postabsorptive state, leucine flux and oxidation were similar in both(More)
Age-related loss of muscle protein may involve a decreased response to anabolic factors of muscle protein synthesis through dysregulation of translation factors. To verify this hypothesis, we simultaneously investigated muscle protein synthesis and expression of some factors implicated in insulin signal transduction during hyperinsulinemia and(More)
OBJECTIVE: To address whether: (1) bioelectrical impedance analysis (BIA) can provide precise and accurate estimates of total body water (TBW) and extracellular water (ECW) in healthy elderly subjects, that display age-induced changes in body composition, (2) BIA models are improved by introducing variables related to geometrical body-shape and(More)
In young men ingesting protein meals, slowly digested proteins (caseins: CAS) induce a higher protein gain than those that are rapidly digested (whey proteins: WP). Our aim was to assess whether or not this is true in elderly men receiving mixed meals. The effects of meals containing either CAS or two different amounts of WP (WP-iN: isonitrogenous with CAS,(More)
BACKGROUND Duchenne muscular dystrophy (DMD) is often associated with obesity, which worsens the handicap early in the course of the disease. Nutritional assessment, however, can be difficult and often misleading in DMD. OBJECTIVE Two methods of estimating body composition in DMD, skinfold-thickness (ST) measurement and bioelectrical impedance analysis(More)
Caloric restriction (CR) delays the onset of age-related mitochondrial abnormalities but does not prevent the decline in ATP production needed to sustain muscle protein fractional synthesis rate (FSR) and contractile activity. We hypothesized that improving mitochondrial activity and FSR using a CR diet with maintained protein intakes could enhance(More)
This study was undertaken to determine whether the protein feeding pattern could induce chronic adaptation of protein turnover. After a 15-day adaptive period, elderly (68 yr) and young (26 yr) women received, for 14 days, a diet providing 200 KJ x kg fat-free mass (FFM)(-1) x day(-1), where the daily protein intake (1.7 g protein x kg FFM(-1) x day(-1))(More)
Fractional protein synthesis rate (FSR) of duodenal mucosa was measured in two groups of six healthy young men, either in the fed state at the end of a 10-day standardized diet or after a 36-h fast. Protein synthesis rate was measured during a 9-h intravenous infusion of [13C]leucine and [2H5]phenylalanine. The fed group also received an intragastric(More)