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Names | |
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IUPAC name 2-azaniumylacetate;(3R)-3-propanoyloxy-4-(trimethylazaniumyl)butanoate | |
Identifiers | |
3D model (JSmol) | |
PubChem CID | |
UNII | |
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Properties | |
C12H24N2O6 | |
Molar mass | 292.332 g·mol−1 |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Glycine propionyl-L-carnitine (GPLC) is a propionyl ester of carnitine that includes an additional glycine component. Due to tissues esterases enzymes, GPLC should act as a prodrug and lead to glycine, carnitine and propionic acid in the body.
GPLC has been shown in two studies to result in an increase in blood levels of nitrate/nitrite (a surrogate marker of nitric oxide; not a direct measure of nitric oxide), when used at a daily dose of 4.5 grams. In one study, GPLC was provided to previously sedentary men and women who were also assigned to supervised aerobic exercise for eight weeks. [1] A significant increase in resting levels of blood nitrate/nitrite was noted for subjects receiving GPLC compared to placebo (in a double blind design). Subjects who received GPLC were also noted as having lower levels of malondialdehyde, a lipid peroxidation biomarker indicating free radical mediated oxidation of lipids. Increased free radical production may be associated with impaired Nitric Oxide bioavailability.
In another study, GPLC or a placebo was provided to resistance trained men for four weeks each, with a two-week washout period between each four-week period, using a double blind design. [2] At the end of each four-week period, resting blood samples were obtained, in addition to blood samples following Isometric exercise, showing significant increases in plasma nitrate/nitrite among those who were given GPLC. It is possible that this increase in nitrate/nitrite may have implications related to enhanced blood flow during acute bouts of exercise.
In addition to regular exercise, nutritional antioxidants may combat free radical formation—as has been reported for GPLC. [1] In this study, subjects received oral GPLC at a dosage of either 1.5 or 4.5 grams per day over the course of an eight-week intervention period. With both dosages, the post-intervention level of malondialdehyde, a marker of lipid peroxidation, was decreased as compared to pre-intervention values. The same was not true for subjects receiving a placebo. These findings highlight the significant antioxidant properties of GPLC. More work using GPLC to combat resistance exercise-induced lipid peroxidation has also noted favorable findings (unpublished data). While many athletes now use GPLC as a component of their dietary supplement regimen,[ citation needed ] future work is needed to investigate the impact of GPLC on decreasing oxidative stress resulting from strenuous exercise.
In support of the above, previous work involving the individual components of GPLC has noted decreased protein and lipid peroxidation following glycine use, [3] with potent antioxidant properties noted for propionyl-L-carnitine. [4]
Although still relatively new in the field of sports nutrition, GPLC has been used by some athletes reporting favorable results in terms of exercise performance and recovery. Preliminary work with previously sedentary subjects failed to indicate performance effects related to VO2max assessed via graded exercise treadmill testing or anaerobic energy assessed via a 30-second cycle sprint. [5] However, a study involving active men noted very favorable performance effects of GPLC, as well as a significant reduction in blood lactic acid, a byproduct of anaerobic metabolism thought to impair muscle performance. [6]
Specifically, in this study conducted by Patrick Jacobs and colleagues, 24 healthy, exercise trained men consumed either 4.5 grams of GPLC or a placebo on two different days separated by one week (double blind, cross-over study design). Ninety minutes following ingestion of the assigned treatment, subjects performed five, maximal effort cycle sprint's, each lasting 10 seconds in duration. They were given one minute of “active” recovery between each sprint. The peak and mean power output, as well as the blood lactic acid, was measured for both conditions. Results indicated that power output was up to 15% higher following the glycine propionyl-l-carnitine trials compared to placebo, while post-exercise blood lactic acid was 15-16% lower compared to placebo. These data are in reference to trained men performing repeated cycle sprints. Therefore, it is difficult to extrapolate these findings to other activities.
In other studies, GPLC has been shown to have no effect on aerobic and anaerobic exercise performance, with results showing that up to 3 grams per day for 8 weeks in conjunction with aerobic-exercise training is ineffective for increasing muscle carnitine content and has no significant effects on aerobic- or anaerobic-exercise performance. [7]
Antioxidants are compounds that inhibit oxidation, a chemical reaction that can produce free radicals. Autoxidation leads to degradation of organic compounds, including living matter. Antioxidants are frequently added to industrial products, such as polymers, fuels, and lubricants, to extend their usable lifetimes. Food are also treated with antioxidants to forestall spoilage, in particular the rancidification of oils and fats. In cells, antioxidants such as glutathione, mycothiol or bacillithiol, and enzyme systems like superoxide dismutase, can prevent damage from oxidative stress.
Nitrate is a polyatomic ion with the chemical formula NO−
3. Salts containing this ion are called nitrates. Nitrates are common components of fertilizers and explosives. Almost all inorganic nitrates are soluble in water. An example of an insoluble nitrate is bismuth oxynitrate.
Glutathione is an antioxidant in plants, animals, fungi, and some bacteria and archaea. Glutathione is capable of preventing damage to important cellular components caused by sources such as reactive oxygen species, free radicals, peroxides, lipid peroxides, and heavy metals. It is a tripeptide with a gamma peptide linkage between the carboxyl group of the glutamate side chain and cysteine. The carboxyl group of the cysteine residue is attached by normal peptide linkage to glycine.
Xanthine oxidase is a form of xanthine oxidoreductase, a type of enzyme that generates reactive oxygen species. These enzymes catalyze the oxidation of hypoxanthine to xanthine and can further catalyze the oxidation of xanthine to uric acid. These enzymes play an important role in the catabolism of purines in some species, including humans.
Carnitine is a quaternary ammonium compound involved in metabolism in most mammals, plants, and some bacteria. In support of energy metabolism, carnitine transports long-chain fatty acids from the cytosol into mitochondria to be oxidized for free energy production, and also participates in removing products of metabolism from cells. Given its key metabolic roles, carnitine is concentrated in tissues like skeletal and cardiac muscle that metabolize fatty acids as an energy source. Generally individuals, including strict vegetarians, synthesize enough L-carnitine in vivo.
Sodium nitrite is an inorganic compound with the chemical formula NaNO2. It is a white to slightly yellowish crystalline powder that is very soluble in water and is hygroscopic. From an industrial perspective, it is the most important nitrite salt. It is a precursor to a variety of organic compounds, such as pharmaceuticals, dyes, and pesticides, but it is probably best known as a food additive used in processed meats and (in some countries) in fish products.
Anaerobic exercise is a type of exercise that breaks down glucose in the body without using oxygen; anaerobic means "without oxygen". In practical terms, this means that anaerobic exercise is more intense, but shorter in duration than aerobic exercise.
In biochemistry and metabolism, beta oxidation (also β-oxidation) is the catabolic process by which fatty acid molecules are broken down in the cytosol in prokaryotes and in the mitochondria in eukaryotes to generate acetyl-CoA, which enters the citric acid cycle, and NADH and FADH2, which are co-enzymes used in the electron transport chain. It is named as such because the beta carbon of the fatty acid undergoes oxidation to a carbonyl group. Beta-oxidation is primarily facilitated by the mitochondrial trifunctional protein, an enzyme complex associated with the inner mitochondrial membrane, although very long chain fatty acids are oxidized in peroxisomes.
Mitochondrial myopathies are types of myopathies associated with mitochondrial disease. Adenosine triphosphate (ATP), the chemical used to provide energy for the cell, cannot be produced sufficiently by oxidative phosphorylation when the mitochondrion is either damaged or missing necessary enzymes or transport proteins. With ATP production deficient in mitochondria, there is an over-reliance on anaerobic glycolysis which leads to lactic acidosis either at rest or exercise-induced.
Interval training is a type of training exercise that involves a series of high-intensity workouts interspersed with rest or break periods. The high-intensity periods are typically at or close to anaerobic exercise, while the recovery periods involve activity of lower intensity. Varying the intensity of effort exercises the heart muscle, providing a cardiovascular workout, improving aerobic capacity and permitting the person to exercise for longer and/or at more intense levels.
Lactate inflection point (LIP) is the exercise intensity at which the blood concentration of lactate and/or lactic acid begins to increase rapidly. It is often expressed as 85% of maximum heart rate or 75% of maximum oxygen intake. When exercising at or below the lactate threshold, any lactate produced by the muscles is removed by the body without it building up.
Denitrifying bacteria are a diverse group of bacteria that encompass many different phyla. This group of bacteria, together with denitrifying fungi and archaea, is capable of performing denitrification as part of the nitrogen cycle. Denitrification is performed by a variety of denitrifying bacteria that are widely distributed in soils and sediments and that use oxidized nitrogen compounds in absence of oxygen as a terminal electron acceptor. They metabolise nitrogenous compounds using various enzymes, turning nitrogen oxides back to nitrogen gas or nitrous oxide.
Acetyl-L-carnitine, ALCAR or ALC, is an acetylated form of L-carnitine. It is naturally produced by the human body, and it is available as a dietary supplement. Acetylcarnitine is broken down in the blood by plasma esterases to carnitine which is used by the body to transport fatty acids into the mitochondria for breakdown.
Sports nutrition is the study and practice of nutrition and diet with regards to improving anyone's athletic performance. Nutrition is an important part of many sports training regimens, being popular in strength sports and endurance sports. Sports nutrition focuses its studies on the type, as well as the quantity of fluids and food taken by an athlete. In addition, it deals with the consumption of nutrients such as vitamins, minerals, supplements and organic substances that include carbohydrates, proteins and fats.
Bioenergetic systems are metabolic processes that relate to the flow of energy in living organisms. Those processes convert energy into adenosine triphosphate (ATP), which is the form suitable for muscular activity. There are two main forms of synthesis of ATP: aerobic, which uses oxygen from the bloodstream, and anaerobic, which does not. Bioenergetics is the field of biology that studies bioenergetic systems.
Cellular waste products are formed as a by-product of cellular respiration, a series of processes and reactions that generate energy for the cell, in the form of ATP. One example of cellular respiration creating cellular waste products are aerobic respiration and anaerobic respiration.
Biological functions of nitric oxide are roles that nitric oxide plays within biology.
Nathan Bryan is an industrial researcher and adjunct assistant professor at the Baylor College of Medicine. He received an undergraduate degree in biochemistry from the University of Texas at Austin and a Ph.D. from Louisiana State University. He studies nitric oxide restoration in humans, and he is co-founder of HumanN, a firm developing products to increase nitric oxide levels.
Saliva testing or Salivaomics is a diagnostic technique that involves laboratory analysis of saliva to identify markers of endocrine, immunologic, inflammatory, infectious, and other types of conditions. Saliva is a useful biological fluid for assaying steroid hormones such as cortisol, genetic material like RNA, proteins such as enzymes and antibodies, and a variety of other substances, including natural metabolites, including saliva nitrite, a biomarker for nitric oxide status. Saliva testing is used to screen for or diagnose numerous conditions and disease states, including Cushing's disease, anovulation, HIV, cancer, parasites, hypogonadism, and allergies. Salivary testing has even been used by the U.S. government to assess circadian rhythm shifts in astronauts before flight and to evaluate hormonal profiles of soldiers undergoing military survival training.
Plácido Navas Lloret is a Spanish Professor of Cell Biology in the Andalusian Center for Developmental Biology at the Pablo de Olavide University in Sevilla, Spain. From 2002 to 2012, Professor Navas served as a board member of the International Coenzyme Q10 Association; since 2013, he has been the chairman of the association.