Associating Inulin with a Pea Protein Improves Fast-Twitch Skeletal Muscle Mass and Muscle Mitochondrial Activities in Old Rats.

Aging is associated with a decline in muscle mass and function, leading to increased risk for mobility limitations and frailty. Dietary interventions incorporating specific nutrients, such as pea proteins or inulin, have shown promise in attenuating age-related muscle loss. This study aimed to investigate the effect of pea proteins given with inulin on skeletal muscle in old rats.

Development of a protein food based on texturized wheat proteins, with high protein digestibility and improved lysine content.

The development of plant-based protein foods may facilitate the decrease in animal product consumption in western countries. Wheat proteins, as a starch coproduct, are available in large amounts and are good candidates for this development. We investigated the effect of a new texturing process on wheat protein digestibility and implemented strategies aimed at enhancing the lysine content of the product developed.

Pea Proteins Have Anabolic Effects Comparable to Milk Proteins on Whole Body Protein Retention and Muscle Protein Metabolism in Old Rats.

Plant proteins are attracting rising interest due to their pro-health benefits and environmental sustainability. However, little is known about the nutritional value of pea proteins when consumed by older people. Herein, we evaluated the digestibility and nutritional efficiency of pea proteins compared to casein and whey proteins in old rats.

Anabolic Properties of Mixed Wheat-Legume Pasta Products in Old Rats: Impact on Whole-Body Protein Retention and Skeletal Muscle Protein Synthesis.

The mechanisms that are responsible for sarcopenia are numerous, but the altered muscle protein anabolic response to food intake that appears with advancing age plays an important role. Dietary protein quality needs to be optimized to counter this phenomenon. Blending different plant proteins is expected to compensate for the lower anabolic capacity of plant-based when compared to animal-based protein sources.

Improving lipid mapping in Genome Scale Metabolic Networks using ontologies.

Introduction: To interpret metabolomic and lipidomic profiles, it is necessary to identify the metabolic reactions that connect the measured molecules. This can be achieved by putting them in the context of genome-scale metabolic network reconstructions. However, mapping experimentally measured molecules onto metabolic networks is challenging due to differences in identifiers and level of annotation between data and metabolic networks, especially for lipids.

Effect of high chronic intake of sucrose on liver metabolism in aging rats. Modulation by rutin and micronutrients.

High-sugar intake and senescence share common deleterious effects, in particular in liver, but combination of these two factors was little studied. Our aims were to examine the effect of a high-sucrose diet in liver of old rats and also the potential benefices of a polyphenol/micronutrient supplementation. Four groups of 22-month-old male rats fed during 5 months with a diet containing either 13 or 62% sucrose, supplemented or not with rutin, vitamin E, A, D, selenium, and zinc were compared.

Supplementing Breakfast with a Vitamin D and Leucine-Enriched Whey Protein Medical Nutrition Drink Enhances Postprandial Muscle Protein Synthesis and Muscle Mass in Healthy Older Men.

A promising strategy to help older adults preserve or build muscle mass is to optimize muscle anabolism through providing an adequate amount of high-quality protein at each meal. This "proof of principle" study investigated the acute effect of supplementing breakfast with a vitamin D and leucine-enriched whey protein medical nutrition drink on postprandial muscle protein synthesis and longer-term effect on muscle mass in healthy older adults. A randomized, placebo-controlled, double-blind study was conducted in 24 healthy older men [mean ± SD: age 71 ± 4 y; body mass index (in kg/m) 24.

Fast digestive, leucine-rich, soluble milk proteins improve muscle protein anabolism, and mitochondrial function in undernourished old rats.

Scope: One strategy to manage malnutrition in older patients is to increase protein and energy intake. Here, we evaluate the influence of protein quality during refeeding on improvement in muscle protein and energy metabolism.

Methods And Results: Twenty-month-old male rats (n = 40) were fed 50% of their spontaneous intake for 12 weeks to induce malnutrition, then refed ad libitum with a standard diet enriched with casein or soluble milk proteins (22%) for 4 weeks.

Vitamin D supplementation restores the blunted muscle protein synthesis response in deficient old rats through an impact on ectopic fat deposition.

We investigated the impact of vitamin D deficiency and repletion on muscle anabolism in old rats. Animals were fed a control (1 IU vitamin D/g, ctrl, n=20) or a vitamin D-depleted diet (VDD; 0 IU, n=30) for 6 months. A subset was thereafter sacrificed in the control (ctrl6) and depleted groups (VDD6).

Repeated cures with paracetamol worsen sarcopenia in old rats with suboptimal food intake.

The availability of all amino acids is of prime importance to prevent the ageing-associated decrease in skeletal muscle mass i.e. sarcopenia.

N-3PUFA differentially modulate palmitate-induced lipotoxicity through alterations of its metabolism in C2C12 muscle cells.

Excessive energy intake leads to fat overload and the formation of lipotoxic compounds mainly derived from the saturated fatty acid palmitate (PAL), thus promoting insulin resistance (IR) in skeletal muscle. N-3 polyunsaturated fatty acids (n-3PUFA) may prevent lipotoxicity and IR. The purpose of this study was to examine the differential effects of n-3PUFA on fatty acid metabolism and insulin sensitivity in muscle cells.

DHA at nutritional doses restores insulin sensitivity in skeletal muscle by preventing lipotoxicity and inflammation.

Skeletal muscle plays a major role in the control of whole body glucose disposal in response to insulin stimulus. Excessive supply of fatty acids to this tissue triggers cellular and molecular disturbances leading to lipotoxicity, inflammation, mitochondrial dysfunctions, impaired insulin response and decreased glucose uptake. This study was conducted to analyze the preventive effect of docosahexaenoic acid (DHA), a long-chain polyunsaturated n-3 fatty acid, against insulin resistance, lipotoxicity and inflammation in skeletal muscle at doses compatible with nutritional supplementation.

Bee pollen improves muscle protein and energy metabolism in malnourished old rats through interfering with the Mtor signaling pathway and mitochondrial activity.

Although the management of malnutrition is a priority in older people, this population shows a resistance to refeeding. Fresh bee pollen contains nutritional substances of interest for malnourished people. The aim was to evaluate the effect of fresh bee pollen supplementation on refeeding efficiency in old malnourished rats.

Increased body fat mass and tissue lipotoxicity associated with ovariectomy or high-fat diet differentially affects bone and skeletal muscle metabolism in rats.

Purpose: The aim of this study was to evaluate and compare the musculoskeletal effects induced by ovariectomy-related fat mass deposition against the musculoskeletal effects caused by a high-fat diet.

Methods: A group of adult female rats was ovariectomized and fed a control diet. Two additional groups were sham-operated and fed a control or a high-fat diet for 19 weeks.

Spreading intake of a leucine-rich fast protein in energy-restricted overweight rats does not improve protein mass.

Objective: Energy restriction decreases fat mass and fat-free mass. Our aim was to prevent the latter using type and timing of protein nutrition as tools.

Methods: Young male Wistar rats were given a high-energy diet for 5 wk and then energy restricted and fed a high-protein diet containing caseins, milk-soluble proteins (MSP), or a casein-MSP mixture (n = 9 per group) as the only source of protein for 3 wk.

Cysteine fluxes across the portal-drained viscera of enterally fed minipigs: effect of an acute intestinal inflammation.

Cysteine is considered as a conditionally indispensable amino acid. Its dietary supply should thus be increased when endogenous synthesis cannot meet metabolic need, such as during inflammatory diseases. However, studies in animal models suggest a high first-pass extraction of dietary cysteine by the intestine, limiting the interest for an oral supplementation.

Increased availability of leucine with leucine-rich whey proteins improves postprandial muscle protein synthesis in aging rats.

Objective: We previously found that aging was characterized by a decreased sensitivity of muscle protein synthesis to leucine and that a free leucine-supplemented diet corrected this defect in old rats and elderly humans. The present experiment was undertaken to evaluate the efficiency of selected leucine-rich proteins to stimulate postprandial muscle protein synthesis in old rats to optimize nutritional protein support in the elderly.

Methods: Sixty rats (22 mo old) received an experimental meal for the first hour of feeding and a standard diet for the rest of the day for 30 d.

Effect of an enteral diet supplemented with a specific blend of amino acid on plasma and muscle protein synthesis in ICU patients.

Background & Aim: Polytrauma patients are characterized by a negative nitrogen balance and muscle wasting. Standard nutrition is relatively inefficient to improve muscle protein turnover. The aim of this study was to investigate the effect of enteral nutrition (EN) supplemented with specific amino acids on protein metabolism in polytrauma patients.

Beneficial effect of amino acid supplementation, especially cysteine, on body nitrogen economy in septic rats.

Background And Aims: Muscle wasting and increased synthesis of proteins and compounds involved in host defense characterize severe injury. The aims of the studies reported were to determine which amino acids exhibited an increased tissue content linked to anabolic processes in infected rats by comparison with healthy pair-fed controls, and to explore whether diets supplemented with these amino acids attenuate the catabolic response to infection.

Methods: Total amino acid content of the liver and the rest of the body were measured in control well-fed rats, in infected rats and their pair-fed controls 2 days after infection.

Leucine-supplemented meal feeding for ten days beneficially affects postprandial muscle protein synthesis in old rats.

Acute leucine supplementation of the diet has been shown to blunt defects in postprandial muscle protein metabolism in old rats. This study was undertaken to determine whether the effect of leucine persists in a 10-d experiment. For this purpose, adult (9 mo) and old (21 mo) rats were fed a semiliquid 18.

Acute phase protein levels and thymus, spleen and plasma protein synthesis rates differ in adult and old rats.

Aging induces a dysregulation of immune and inflammation functions that may affect protein synthesis rates in lymphoid tissue and plasma proteins. We quantified in vivo synthesis rates of thymus, spleen and plasma proteins, including albumin and acute phase proteins, in adult (8 mo old) and old (22 mo old) rats using the flooding dose method [L-(1-(13)C) phenylalanine]. Immunosenescence was reflected by thymus atrophy and spleen hypertrophy in old rats but not in adult rats.

Oligonucleotide covalent modifications by estrogen quinones evidenced by use of liquid chromatography coupled to negative electrospray ionization tandem mass spectrometry.

Liquid chromatography coupled to tandem mass spectrometry has been used for the detection and the structural characterization of T-rich model oligonucleotides covalently modified by estradiol-2,3-quinone. After separation by gradient elution, adducts were analyzed by negative electrospray mass spectrometry, enabling to evidence and localize the modifications in the oligonucleotide sequence. Modifications by one molecule of estrogen were evidenced on purines (A, G) whereas no reaction was observed on pyrimidic bases (T).

Postprandial stimulation of muscle protein synthesis in old rats can be restored by a leucine-supplemented meal.

Aging is characterized by a progressive loss of muscle mass. A decrease of muscle protein synthesis stimulation has been detected in the postprandial state and correlated to a decrease of muscle protein synthesis sensitivity to leucine in vitro. This study was undertaken to examine the effect of a leucine-supplemented meal on postprandial (PP) muscle protein synthesis during aging.

Methionine transsulfuration is increased during sepsis in rats.

Methionine transsulfuration in plasma and liver, and plasma methionine and cysteine kinetics were investigated in vivo during the acute phase of sepsis in rats. Rats were infected with an intravenous injection of live Escherichia coli, and control pair-fed rats were injected with saline. Two days after injection, the rats were infused for 6 h with [(35)S]methionine and [(15)N]cysteine.