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Arginine C6H14N4O2 精胺酸
The chemical name of arginine is 2-amino-5-guanidovaleric acid. It is
an essential amino acid, C6H14N4O2, a major component of proteins, produced by the hydrolysis or
digestion of proteins. It is one of the hexone bases (Schulze and Steiger,
1886), and it supplies the amidine group for the synthesis of creatine.
It contains the guanido group that has a pKa of greater than 12, so that it
carries a permanent positive charge at physiological pH. It becomes an
essential amino acid when the body is under stress or is in an injured
state.
精氨酸化學名為:2-氨基-5-胍基戊酸; L-蛋白氨基酸。它是一種重要的氨基酸，C6H14N4O2，為蛋白質組成重要部份，是水解或消化蛋白质所得的。它是異己酮鹼之一種。
Lack of dietary arginine results in depressed growth. Arginine deficiency
syndrome is observed in human babies born with a phosphate synthetase
deficiency. Normal growth and development in these infants are achieved by
adding arginine to their diet.
Arginine deficiency leads to carbamyl phosphate overproduction in the
mitochondria due to inadequate ornithine supply. Arginine-deficient
diets in males causes decreased sperm counts. Free and bound arginine are
found in abundance in human male sperm and arginine has been found to
stimulate sperm motility.
There are two sources of arginine: arginine in the food chain and free-form
arginine from supplements. Food-source arginine is found in abundance
in turkey, chicken and other meats. Nonfood-source arginine is called L-arginine
and is created through a fermentation process which separates arginine from all other proteins. In
the presence of food and other amino acids, L-arginine will act
like food-source arginine but when L-arginine is separated from its nutrient
boundaries by the removal of all other amino acids, then L-arginine
undertakes a different role, becoming capable of crossing the blood-brain
barrier and stimulating growth
hormone release secreted by the anterior pituitary.
Growth hormone serum levels peak during adolescence and begin to drop after
age 23. Aging reduces natural growth hormone production, which
results in added body fat, reduced muscle tissue, slowed healing, lack of
elasticity in the skin and reduced immune function. Human pituitary
growth hormone secretion is evidenced in human males, females and children
following intravenous administration of 30 grams of arginine (in 30 minutes) in adults
and 0.5 grams/kilogram of bodyweight in children. Female
response is somewhat higher than male response. Oral administration of L-arginine
also results in the release of Human Growth Hormone.
Tumor suppression is evidenced in the presence of L-arginine. In the Barbul
study, tumors recurred in 100% of the control animals. But in the
arginine-supplemented group, only about 60% of the tumors recurred and the
animals with tumors survived longer. Supplementation of arginine in the diet
inhibits development and increase in size of cancerous tumors, both chemically induced and naturally occurring.
Insulin can block growth hormone release, so high serum insulin levels are
counterproductive to growth hormone release. Insulin itself is capable of
stimulating muscle growth, but it also strongly stimulates fat storage.
Muscle growth stimulation from insulin is minuscule compared to muscle
growth stimulated by growth hormone.
Arginine is a natural constituent of dietary proteins
and has a low toxicity in otherwise healthy individuals.
Source:
1.
OMD
2.
Dorland's Illustrated Medical Dictionary
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