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Nitrogen supply is pivotal for the maintenance of life. Amino acids can be utilized to synthesize both glucose and lipids. The opposite, i.e., production of amino acids from either one of them, is not possible in the absence of other... more
Nitrogen supply is pivotal for the maintenance of life. Amino acids can be utilized to synthesize both glucose and lipids. The opposite, i.e., production of amino acids from either one of them, is not possible in the absence of other amino acids as donors of nitrogen. The quality of amino acid content in protein has been re-evaluated recently, and the relevance of essential amino acids has been repeatedly underlined. Essential amino acid requirements in different mammals are not identical, and ratios among them should be taken into account when projecting an efficient formulation. Recent research has demonstrated that genes respond to different qualities and quantities of nutritional supply, and increased provision of essential amino acids increases lifespan in animal experiments through mitochondriogenesis and maintenance of elevated rates of synthesis of anti-oxidant molecules. Moreover, genetic expression of key controllers of synthesis, like mTOR, may be particularly important f...
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... Advanced glycation end products and nephrotoxicity of high protein diets. Clin J Am Soc Nephrol 2006; 1: 1293-9. 7. Bellizzi V, Di Iorio BR, De Nicola L, et al; on behalf of the ERIKA study group. ... 35. Brocca A, D'Antona G,... more
... Advanced glycation end products and nephrotoxicity of high protein diets. Clin J Am Soc Nephrol 2006; 1: 1293-9. 7. Bellizzi V, Di Iorio BR, De Nicola L, et al; on behalf of the ERIKA study group. ... 35. Brocca A, D'Antona G, Bachi A, Pellegrino MA. ...
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Arginine is one of the 20 amino acids (AA) found in proteins and synthesized by human cells. However, arginine is also the substrate for a series of reactions leading to the synthesis of other AA and is an obligatory substrate for two... more
Arginine is one of the 20 amino acids (AA) found in proteins and synthesized by human cells. However, arginine is also the substrate for a series of reactions leading to the synthesis of other AA and is an obligatory substrate for two enzymes with diverging actions, arginases and nitric oxide synthases (NOS), giving origin to urea and NO, respectively. NO is a very potent vasodilator when produced by endothelial NOS (eNOS). The 'arginine paradox' is the fact that, despite intracellular physiological concentration of arginine being several hundred micromoles per liter, far exceeding the ∼5 μM K(M) of eNOS, the acute provision of exogenous arginine still increases NO production. Clinically, an additional paradox is that the largest controlled study on chronic oral arginine supplementation in patients after myocardial infarction had to be interrupted for excess mortality in treated patients. Expression and activity of arginases, which produce urea and divert arginine from NOS, are positively related to exogenous arginine supplementation. Therefore, the more arginine is introduced, the more it is destroyed, eventually leading to impaired NO production. In this review, conditions influencing the low arginine concentrations found in plasma will be reviewed, revising the paradigm that simple replenishment of what is lacking will always produce beneficial consequences.
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The liver sustains the greatest damage from ethanol (EtOH) abuse. EtOH and its metabolites impair hepatocyte metabolism, causing intracellular accumulation of proteins and lipids and increasing radical oxygen species production. These... more
The liver sustains the greatest damage from ethanol (EtOH) abuse. EtOH and its metabolites impair hepatocyte metabolism, causing intracellular accumulation of proteins and lipids and increasing radical oxygen species production. These processes are toxic to the mitochondrial respiratory chain and to mitochondrial DNA. We have recently shown that supplementating the diet of rodents with an essential amino acid-enriched mixture (EAAem) significantly increases mitochondrial mass and number in cardiac and skeletal muscles and improves mitochondrial function in aged animals. Thus, in this study we sought to test whether EAAem supplementation could reduce EtOH-induced liver damage. Groups of adult male Wistar rats were fed a standard diet and water ad libitum (the control group), drinking water with 20 percent EtOH (the EtOH group), or drinking water with 20 percent EtOH and EAAem supplementation (1.5 g/kg/day) (the EtOH+EAAem group) for 2 months. The blood EtOH concentration was measured...
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Medical research and consequently therapy are undergoing dramatic transformation. New science on genomics and proteomics has given us important information on the pathophysiology of many cardiac diseases and personalized responses to... more
Medical research and consequently therapy are undergoing dramatic transformation. New science on genomics and proteomics has given us important information on the pathophysiology of many cardiac diseases and personalized responses to specific patient-oriented therapies. The application of cellular genetic and proteome tests is a promising field of research and their clinical use can allow us to both: 1) understand the causes and evolution of heart diseases such as ischemia and heart failure better, 2) lead to personalized medicine. This article focuses on the basic intracellular-related evidence and the unsolved problems and complexity of intracellular signaling that still need to be studied to understand personalized therapies better. In addition, we provide preliminary clinical data that support the potentiality of this new but fundamental approach of curing patients according to their genetic expression and/or protein activation that influence personalized development and the man...
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Research Interests: Metabolism, Muscle strength, Growth Hormone, Cortisol, Humans, and 19 moreTestosterone, Human Growth Hormone, Blood sampling, Hormones, Male, Resistance Training, Dietary Supplements, Creatine Kinase, Clinical Sciences, Amino Acids, Uric Acid, Adult, Amino Acid Profile, Sex hormone-binding globulin, Growth Factor, Muscle Damage, Exercise Tolerance, Bench Press, and Hemoglobins
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Research Interests: Strength & Conditioning, Skeletal muscle biology, Anthropometry, Treatment Outcome, Adolescent, and 18 moreProbability, Muscle strength, Humans, Body Composition, Male, Resistance Training, Weight Lifting, Dietary Supplements, Amino Acids, Adult, Analysis of Variance, Muscle Fatigue, Amino Acid Profile, Indexation, Reference Values, Bench Press, Peak Power, and Physical Endurance
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The structural, morphological and surface features on two MCC powders of the same commercial type (Avicel PH 102), but coming from different countries (The Netherlands and Hong Kong) and vendors (DMV International and Mingtai Chemical... more
The structural, morphological and surface features on two MCC powders of the same commercial type (Avicel PH 102), but coming from different countries (The Netherlands and Hong Kong) and vendors (DMV International and Mingtai Chemical Co., Ltd., respectively), have been investigated and compared, by means of the X-ray diffraction, SEM and BET and polymerization degree determination. TGA and water sorption from saturated vapor experiments have been applied to characterize and compare the MCC/water interactions of the two samples. The results were integrated by studies of preferential sorption from binary aqueous/organic solvents.
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The aims of the present study were as follows: (1) to examine the adaptational changes to chronic endurance voluntary exercise and (2) to investigate the effects of amino acid supplementation on the adaptational changes induced by... more
The aims of the present study were as follows: (1) to examine the adaptational changes to chronic endurance voluntary exercise and (2) to investigate the effects of amino acid supplementation on the adaptational changes induced by endurance training in hindlimb (gastrocnemius, tibialis, soleus) and respiratory (diaphragm) muscles of mice. Male C57Bl6 mice were divided in four groups: control sedentary, sedentary supplemented with amino acid mixture (BigOne, 1.5 mg g day(-1) in drinking water for 8 weeks), running (free access to running wheels for 8 weeks), and running supplemented with amino acid mixture. Myosin heavy chain (MHC) isoform distribution was determined in all muscles considered. Fiber cross-sectional area (CSA) was measured in the soleus muscle. In all muscles except the tibialis, endurance training was associated with an overall shift towards the expression of slower MHC isoforms. Amino acid supplementation produced a shift towards the expression of faster MHC isoforms in the soleus and diaphragm muscles, and partially antagonized the effects of training. Immunohistochemical analysis of CSA of individual muscle fibers from the soleus muscle suggests that voluntary running produced a decrease in the size of type 1 fibers, and amino acid supplementation during training resulted in an increase in size in both type 1 and type 2A fibers. Collectively, these results suggest that the endurance adaptations induced by voluntary running depend on the muscle type, and that amino acid supplementation is able to modulate both fiber size and MHC isoform composition of skeletal muscles in sedentary and exercised mice.
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During ischemia and heart failure, myocardial cells suffer for chronic energy starvation resulting in metabolic and contractile dysfunction. In normal conditions fatty acids, glucose, and lactate are the principal oxidative fuels in... more
During ischemia and heart failure, myocardial cells suffer for chronic energy starvation resulting in metabolic and contractile dysfunction. In normal conditions fatty acids, glucose, and lactate are the principal oxidative fuels in myocardium, while amino acids serve a minor role as an oxidative fuel. However, in pathological conditions, myocardial uptake of several amino acids increases significantly as a consequence of a metabolic remodelling. Amino acids are involved in a variety of key biochemical and physiological activities, that counteract the deleterious cellular effects of reduced oxygen availability. Several amino acids are a direct source of substrate for energy production, and they modulate the activity of some enzymes involved in the glucose metabolism. They increase contractile performance both in isolated animal and human myocardium. Furthermore, amino acids improve the oxidative stress counteracting the action of radical oxygen species, being either precursors of glutathione synthesis, or of substrate of nitric oxide biosynthesis; they act on endothelial function and increase protein synthetic efficiency of myocardial cells by regulating gene expression and modulating hormonal activity. An amount of studies have demonstrated that amino acids administration, on patients with ischemic heart disease and heart failure, can improve several clinical endpoints. Here, we present an overview of the principal effects of the most experienced amino acids and of amino acid derivatives on ischemia and heart failure.