Arginine

Some important facts about Arginine:
Arginine, an essential amino acid, has a positively charged guanidino group. Arginine is well designed to bind the phosphate anion, and is often found in the active centers of proteins that bind phosphorylated substrates. As a cation, arginine, as well as lysine, plays a role in maintaining the overall charge balance of a protein. There are 6 codons in the genetic code for arginine, yet, although this large a number of codons is normally associated with a high frequency of the particular amino acid in proteins, arginine is one of the least frequent amino acids. The discrepancy between the frequency of the amino acid in proteins and the number of codons is greater for arginine than for any other amino acid.
Arginine has several roles in the body, such assisting in wound healing, helping remove excess ammonia from the body, stimulating immune function, and promoting secretion of several hormones, including glucagon, insulin, and growth hormone. Arginine is also needed to increase protein synthesis, which can in turn increase cellular replication. Arginine is a complex amino acid that is often found at the active (or catalytic) site in proteins and enzymes due to its amine-containing side chain. Although Arginine is considered an essential amino acid (it must be obtained through the diet), this is true only during the juvenile period in humans.
Arginine is incorporated in proteins at about a 4.7 percent on a per-mole basis when compared to the other amino acids. Natural sources of Arginine are brown rice, nuts, popcorn, raisins, and whole-wheat products. Studies have shown that is has improved immune responses to bacteria, viruses & tumor cells; promotes wound healing and regeneration of the liver; causes the release of growth hormones; considered crucial for optimal muscle growth and tissue repair. Arginine also plays an important role in nitrogen metabolism. In the urea cycle, the enzyme arginase cleaves (hydrolyzes) the guanidinium group to yield urea and the L-amino acid ornithine. Ornithine is lysine with one fewer methylene groups in the side chain. L-ornithine is not normally found in proteins.

Benefits of arginine:
This amino acid has several roles in the body, such as helping in wound healing, helping remove excess ammonia from the body, stimulating immune function, and promoting secretion of several hormones, including glucagon, insulin, and growth hormone.
Severe burns, infections, and injuries can decrease the body's supply of arginine. It is used in hospitals as an immune supplement to speed recovery from severe illness. Arginine can also be used to prevent colds, asthma, kidney failure, and recovery from illness and injury.
This amino acid also helps in the synthesis of proteins synthesis, which can in turn increase cellular replication. Therefore, arginine may help people with inadequate numbers of certain cells. For example, studies have found that men with low sperm counts experienced an increase in the number of sperm when they supplemented with arginine.
Some evidence also suggests that arginine may help to regulate the cholesterol levels. It makes the blood thin by reducing platelet aggregation. It helps in the wound healing by increasing the protein synthesis in the body.
Arginine can be used to help treat conditions such as congestive heart failure, impotence, sexual dysfunction in women, intermittent claudication and interstitial cystitis. Nitric oxide a precursor of arginine also plays a role in the brain and nervous system.
It acts as a chemical messenger that is essential for good memory and learning, as well as in the regulation of the sleep-wake cycle, among other functions.

Symptoms of high intake:
When taking arginine up to moderate doses of 2 to 3 g per day, arginine appears to be free of side effects, however, minor digestive disturbances can occur. Higher doses of arginine can increase stomach acid.
This can harm people with heartburn, ulcers, or who are already taking drugs that are harmful to the stomach. Arginine increases stomach acid by stimulating production of gastrin, a hormone that increases stomach acid. It is also studied that higher doses of arginine can also lead to the cancer growth in the body.

It is not recommended for:
Arginine may alter potassium levels, especially in people with liver disease. People with kidney disease and those who take ACE inhibitors or potassium sparing diuretics should not use supplemental arginine unless they are under medical supervision. It is not safe to take higher doses of arginine in pregnant and nursing women and children.

Daily requirement:
A typical dosage of arginine is 2 to 3 g of arginine per day. In clinical trials, it is used in dosages of 5 to 15 g for congestive heart failure. While some people with serious infections, burns, or other trauma should take arginine, a physician must determine appropriate amounts.

Who need more?
People with angina pectoris, low blood pressure may need higher intakes of arginine. But a person should increase its intake of arginine under medical supervision. Higher intakes of arginine can also help in people with erectile problems but under the guidance of physician. Some have also suggested that the supplements can improve the function of blood vessels, enhance coronary blood flow Higher intakes may also be needed during times of unusual stress including infections, burns, and injury.

Sources of arginine:
Dairy, meat and poultry and fish are good sources of arginine. Nuts and chocolate also contain significant amounts of this arginine.