Glutamine

Glutamine is an amino acid that is classified under the nonessential group since it can be readily synthesized by various tissues in the body, including the skeletal muscles, liver, and adipose tissue. Further developments in science stated however that conditionally, glutamine can be an essential amino acid. When the metabolic demand for glutamine exceeds the amount available in the free glutamine pool and that which can be provided by de novo synthesis, then glutamine becomes essential to the body.

How Glutamine works

The demand for plasma glutamine experiences a marked high during exercise or other times when stress is applied to the body’s normal metabolic rate, such as fasting, severe injury, illness, et cetera. Various cells of the immune system such as lymphocytes and macrophages depend on this substance as their primary fuel source. So for instance, in the event of an illness, the immunological response is mounted in order to counteract the symptoms. The cells’ demand for glutamine therefore increases along with the heavy demand for more action in the performance of their functions.

About 40-50% of glutamine is consumed by the enterocytes of the small intestines, which makes them the largest consumers of this substance. Additionally, this substance is required for the synthesis of nucleotides in the cell nuclei. This explains the increased demand for glutamine during cell division. For rapid growth and development, a sufficient supply of glutamine is therefore important. De novo synthesis of the substance might not be enough to supply the amount needed to meet the physiological demand during times of severe, metabolic stress when the amount of free glutamine is rapidly depleted.

Another important system that needs adequate amount of glutamine is the skeletal system. The primary sites for glutamine synthesis are the skeletal muscles. This is why approximately 60% of the free amino acids stored in the skeletal muscles are glutamine. Within the plasma, this substance is also the most abundant amino acid. Cortisol, a glucocorticoid hormone, is released during times of stress. It release prompts the proteolysis of muscle proteins and the release of glutamine into the plasma to support the increased demand for free glutamine.

Hypoglycemic states, such as fasting for approximately 12 hours, result in the branched-chain amino acids within the muscle undergoing the transamination process to yield keto-acids which are precursors for glucogeogenesis or ketogenesis. This results in the generation of glutamate and alanine. Glutamate is the substance which when synthesized is converted into glutamine and ammonia.

Ergogenic Effects

Glutamine plays a significant role in the maintenance of muscle mass during physiological stress. Supplementation of this substance may promote nitrogen retention and prevent the loss of muscle protein. For this reason, many bodybuilding enthusiasts use this substance in their supplemental drugs to keep their muscles toned and maintain their mass.

Commercial Availability and General Use

A month’s supply of glutamine costs around $14 to $54. The substance is typically sold in the form of gel capsules and powders. It is sold in major health or nutrition stores and an ingredient in many dietary supplements, such as protein powders.

One important thing to note about this substance is that it is relatively unstable in solution. So if you use glutamine powder and mix it into solution, it must be consumed shortly. Some manufacturers recommend that its consumption be divided in dosages throughout the day. Other suggestions include consuming it shortly before sleep and after waking.