Free essential amino acid feeding improves endurance during resistance training via DRP1-dependent mitochondrial remodelling.

Background: Loss of muscle strength and endurance with aging or in various conditions negatively affects quality of life. Resistance exercise training (RET) is the most powerful means to improve muscle mass and strength, but it does not generally lead to improvements in endurance capacity. Free essential amino acids (EAAs) act as precursors and stimuli for synthesis of both mitochondrial and myofibrillar proteins that could potentially confer endurance and strength gains.

Balanced Free Essential Amino Acids and Resistance Exercise Training Synergistically Improve Dexamethasone-Induced Impairments in Muscle Strength, Endurance, and Insulin Sensitivity in Mice.

Our previous study shows that an essential amino acid (EAA)-enriched diet attenuates dexamethasone (DEX)-induced declines in muscle mass and strength, as well as insulin sensitivity, but does not affect endurance. In the present study, we hypothesized that the beneficial effects will be synergized by adding resistance exercise training (RET) to EAA, and diet-free EAA would improve endurance. To test hypotheses, mice were randomized into the following four groups: control, EAA, RET, and EAA+RET.

Essential Amino Acid-Enriched Diet Alleviates Dexamethasone-Induced Loss of Muscle Mass and Function through Stimulation of Myofibrillar Protein Synthesis and Improves Glucose Metabolism in Mice.

Dexamethasone (DEX) induces dysregulation of protein turnover, leading to muscle atrophy and impairment of glucose metabolism. Positive protein balance, i.e.

Myostatin Inhibition-Induced Increase in Muscle Mass and Strength Was Amplified by Resistance Exercise Training, and Dietary Essential Amino Acids Improved Muscle Quality in Mice.

It has been frequently reported that myostatin inhibition increases muscle mass, but decreases muscle quality (i.e., strength/muscle mass).

The Anabolic Response to Dietary Protein Is Not Limited by the Maximal Stimulation of Protein Synthesis in Healthy Older Adults: A Randomized Crossover Trial.

We have recently demonstrated in young adults that an anabolic response with mixed meal protein intake above ~35 g/meal, previously recognized as an "optimal" protein dose, was further stimulated. However, it is unknown if this applies to older adults. We therefore examined anabolic response to a mixed meal containing either 35 g (MOD, moderate amount of protein) or 70 g (HIGH, high amount of protein) in a randomized cross-over metabolic study in older adults ( = 8).

Net protein balance correlates with expression of autophagy, mitochondrial biogenesis, and fat metabolism-related genes in skeletal muscle from older adults.

The mechanisms leading to sarcopenia, the main cause for frailty in older adults, are still unclear. Autophagy and the ubiquitin-proteasome system (UPS) may play a role in mediating muscle protein breakdown related to sarcopenia. In addition to loss of muscle mass, compromised muscle performance observed in sarcopenic patients has been linked to muscle mitochondria dysfunction.

Quantifications of Lipid Kinetics Using Stable Isotope Tracer Methodology.

Like other bodily materials, lipids such as plasma triacylglycerol, cholesterols, and free fatty acids are in a dynamic state of constant turnover (i.e., synthesis, breakdown, oxidation, and/or conversion to other compounds) as essential processes for achieving dynamic homeostasis in the body.

Understanding Muscle Protein Dynamics: Technical Considerations for Advancing Sarcopenia Research.

Sarcopenia, which is the loss of muscle mass and strength that occur with aging, involves imbalanced muscle protein turnover (i.e., protein breakdown exceeding synthesis), which in turn exacerbates other clinical conditions such as type 2 diabetes mellitus, obesity, osteoporosis, and cancer, thereby worsening the quality of life in older adults.

The synergistic effect of protein complex supplementation combined with 12 weeks of resistance training on isokinetic muscular function in untrained young males.

Purpose: Resistance exercise training (RET) and an additional intake of dietary protein supplements may improve muscle mass and muscular function, and reduce inflammatory markers. The types, amount, and timing of dietary protein supplements are important for the synergistic effects of resistance training and dietary protein supplements. We hypothesized that a 25.

Pathway engineering of Enterobacter aerogenes to improve acetoin production by reducing by-products formation.

Enterobacter aerogenes was metabolically engineered for acetoin production. To remove the pathway enzymes that catalyzed the formation of by-products, the three genes encoding a lactate dehydrogenase (ldhA) and two 2,3-butanediol dehydrogenases (budC, and dhaD), respectively, were deleted from the genome. The acetoin production was higher under highly aerobic conditions.

l-Carnitine supplement reduces skeletal muscle atrophy induced by prolonged hindlimb suspension in rats.

l-Carnitine was recently found to downregulate the ubiquitin proteasome pathway (UPP) and increase insulin-like growth factor 1 concentrations in animal models. However, the effect of l-carnitine administration on disuse muscle atrophy induced by hindlimb suspension has not yet been studied. Thus, we hypothesized that l-carnitine may have a protective effect on muscle atrophy induced by hindlimb suspension via the Akt1/mTOR and/or UPP.

In Vivo Evaluation of Commercially Available Gel-Type Polyethylene Glycol Membrane for Carrier of Recombinant Human Bone Morphogenetic Protein-2.

Purpose: This study evaluated a commercially available, 3-dimensional gel-type polyethylene glycol (PEG) membrane as a carrier for recombinant human bone morphogenetic protein-2 (rhBMP-2) using a rat calvarial defect model. Another gel-type carrier, fibrin-fibronectin system (FFS), was used as a positive control.

Materials And Methods: Critical-size defects were made in the rat calvarium, which were allocated to 1 of 10 groups comprising 2 healing periods and biomaterial conditions: 1) sham control, 2) FFS only, 3) FFS plus BMP-2, 4) PEG only, and 5) PEG plus BMP-2.

Protective effect of branched chain amino acids on hindlimb suspension-induced muscle atrophy in growing rats.

Purpose: The effect of BCAA (branched chain amino acid) administration on muscle atrophy during growth phases is not well known. We investigated whether BCAA administration can prevent the muscle atrophy induced by hindlimb suspension in growing male rats.

Methods: Male Wistar rats were assigned to 1 of 2 groups (n = 7/group): hindlimb suspension and hindlimb suspension with oral BCAA administration (600 mg·kg(-1)·day(-1), valine 1: leucine 2: isoleucine 1).

Choline Essentiality and Its Requirement in Diets for Juvenile Parrot Fish (Oplegnathus fasciatus).

A 12-wk feeding trial was conducted to evaluate the essentiality of choline supplementation in diets for parrot fish. Five isonitrogenous and isocaloric diets were supplemented with 0 (as control), 500, 1,000, and 2,000 mg choline per kg diet, and a positive control diet without choline contained 0.3% of 2-amino-2-methyl-1-propanol as choline biosynthesis inhibitor (designated as Con, C500, C1000, C2000 and Con(+), respectively).

Osteoinductive activity of biphasic calcium phosphate with different rhBMP-2 doses in rats.

Objective: The aim of the current study was to determine whether a hydroxyapatite (HA)/beta-tricalcium phosphate (β-TCP) ratio of 20/80 impregnated with recombinant human bone morphogenetic protein (rhBMP-2) enhances new bone formation and to evaluate the dose-dependent response of rhBMP-2.

Study Design: Critical-sized calvarial defects were made in rats, and biphasic calcium phosphate (BCP) with different rhBMP-2 doses was loaded into rat calvarial defects. The animals were allowed to heal for either 2 or 8 weeks.

Randomized clinical trial on the efficacy of Escherichia coli-derived rhBMP-2 with β-TCP/HA in extraction socket.

Purpose: This randomized clinical trial was conducted to assess the safety and effectiveness of the ErhBMP-2 in alveolar bone regeneration as well as preservation of the β-TCP bone graft material that contains ErhBMP-2.

Materials And Methods: This study involved 72 patients at the 3 study centers. The patients, who were divided into 2 groups: the experiment group who had ErhBMP-2 coated TCP/HA and the control group who had TCP/HA graft material alone transplanted immediately after tooth extraction.

Endoscopic fibrin glue injection for closure of pancreatocutaneous fistula following transgastric endoscopic necrosectomy.

Transgastric endoscopic necrosectomy has been recently introduced as the effective and alternative management of infected pancreatic necrosis and pancreatic abscess. However, up to 40% of patients who undergo endoscopic necrosectomy may need an additional percutaneous approach for subsequent peripancreatic fluid collection or non-resolution of pancreatic necrosis. This percutaneous approach may lead to persistent pancreatocutaneous fistula, which remains a serious problem and usually requires prolonged hospitalization, or even open-abdominal surgery.