What is Glutamine?
Glutamine is considered by most athletes to be an essential part of their nutritional program. Glutamine is the most abundant single amino acid which comprises 61% of the free intracellular amino acid pool (most abundant amino acid in muscle tissue), while BCAA's comprise 8.4% of the pool. Glutamine's unique structure, containing two nitrogen side chains, consists of 19% nitrogen - making it the primary transporter of nitrogen into the muscle cells. Glutamine has become more prominent as new studies reveal its unique contribution to protein synthesis (muscle growth), anti-proteolytic (prevents muscle tissue) breakdown functions and growth hormone elevating effects. Due to these effects, Glutamine plays an important part in your body by aiding recovery of muscle cells.
Glutamine concentrations fall markedly after training and remain low until complete recovery. In this condition research shows glutamine levels are significantly reduced, taking up to one month to return to baseline. In athletes, glutamine has been used as a marker to indicate overtraining. This fall in glutamine is catabolic to muscle tissue. BCAA's (comprising 37% of total muscle) are debranched from skeletal muscle, and the resulting molecules are used to synthesis glutamine. In the catabolic state, glutamine is the first amino acid used to correct that deficiency. Glutamine drives protein into the muscle cell where it is synthesized for growth. This means that additional Glutamine is necessary during periods of stress (such as intense weight training which induces a catabolic state which has been shown to uniformly decrease Glutamine levels by 50%, taking several hours to return to normal levels). Additionally, L-Glutamine also decreases protein degradation (BCAA catabolism), resulting in bigger, stronger muscle cells.
The most abundant amino acid in the bloodstream, L-glutamine fulfills a number of biochemical needs. It operates as a nitrogen shuttle, taking up excess ammonia and forming urea. It can contribute to the production of other amino acids, glucose, nucleotides, protein, and glutathione. Glutamine is primarily formed and stored in skeletal muscle and lungs, and is the principal metabolic fuel for small intestine enterocytes, lymphocytes, macrophages, and fibroblasts. Supplemental use of glutamine, either in oral, enteral, or parenteral form, increases intestinal villous height, stimulates gut mucosal cellular proliferation, and maintains mucosal integrity. It also prevents intestinal hyperpermeability and bacterial translocation, which may be involved in sepsis and the development of multiple organ failure. L-glutamine use has been found to be of great importance in the treatment of trauma and surgery patients, and has been shown to decrease the incidence of infection in these patients. Cancer patients often develop muscle glutamine depletion, due to uptake by tumors and chronic protein catabolism. Glutamine may be helpful in offsetting this depletion; however, it may also stimulate the growth of some tumors. The use of glutamine with cancer chemotherapy and radiotherapy seems to prevent gut and oral toxic side-effects, and may even increase the effectiveness of some chemotherapy drugs. Altern Med Rev 1999;4:239-248.
Glutamine is considered a non-essential amino acid. Under certain pathological circumstances the body's tissues need more glutamine than the overall amount supplied by diet and de novo synthesis. During catabolic stress, for instance, intracellular glutamine levels can drop more than 50 percent, and plasma concentration falls 30 percent. It is under these circumstances that supplemental glutamine becomes necessary.
Skeletal muscle contains the greatest intracellular concentration of glutamine, comprising up to 60 percent of total body glutamine stores, and is considered the primary storage depot of glutamine, and thus the primary exporter of glutamine to other tissues. In times of metabolic stress, glutamine is released into circulation, where it is transported to the tissue in need. Intracellular skeletal muscle glutamine concentration is affected by various insults, including injury, sepsis, prolonged stress, starvation, and the use of glucocorticoids. Besides skeletal muscle, the lungs are the next largest producer of glutamine.
Glutamine can be converted to other amino acids, to glucose in the liver, and contributes to nucleotide, amino sugar, and protein biosynthesis. Glutamine is one of the three amino acids involved in glutathione synthesis. Glutathione, an important intracellular antioxidant and hepatic detoxifier, is comprised of glutamic acid, cysteine, and glycine.
Supplement with Glutamine. "Look at it this way; nobody gets big and strong if you're sick. If your digestion is compromised, all that super nutrition will just pass you by. Both the digestive tract and the immune system both crave Glutamine as a fuel. Most bodybuilders eat more than enough protein from the supermarket, but they don't get enough Glutamine. The body uses Glutamine to shuttle ammonia around in the body, so blood levels of Glutamine try to maintain constant. Unfortunately, the Glutamin storehouse is your muscle cells, so unless you replenish with supplemental Glutamine, your muscles can start looking like day-old helium balloons (smaller and flabby)" Daniel Duchaine
Glutamine is a non-essential amino acid that is synthesized and absorbed by various organs of the body including the stomach, intestines, and muscles. Strenuous prolonged exercise, such as a marathon or intense weight training decreases the body's glutamine levels. This in turn affects various bodily functions, including immune system function. Since glutamine acts as an energy source for the cells of the immune system, its suppression that occurs after exercise is believed to contribute to infections athletes often develop during periods of intense training. Recent research has shown that supplementing with glutamine can help decrease the likelihood of suffering from illness due to infection.
"Athletes in one study took either 5 grams of glutamine or a placebo immediately after participating in prolonged exercise such as rowing, a 10k run or a marathon. The subjects taking supplemental glutamine had one half the infections than the subjects taking a placebo supplement. Researchers believe that taking supplemental glutamine helps to restore the body's levels of glutamine that are reduced after strenuous exercise. This in turn helps to maintain immune system function that is normally reduced as a result of strenuous exercise." Curt Pedersen