L-arginine is a non-essential amino acid, which not only participates in the metabolism of body tissues, but also is closely related to protein metabolism and immune function of the body.
Arginine is used as an immune nutrient in physiological state, and the arginine synthesized by the body itself can meet the metabolic needs. However, in the state of stress, trauma or rapid growth, the body's demand for arginine greatly increases, and its own synthesis cannot meet the needs of physiological metabolism, so it must be replenished in time. Therefore, arginine is defined as a conditionally essential amino acid or a semi-essential amino acid.
In addition to the nutritional functions of general amino acids, arginine also serves as a precursor of a signaling molecule (nitric oxide, NO) in the body,,and derives many important biological functions. It plays an important role in the maintenance of immune function during exercise.
Endogenous synthesis of arginine
Arginine can be synthesized from glutamine (Gln) and proline (Pro), and plasma citrulline and ornithine in mitochondria are precursors for arginine synthesis. Most of the enzymes involved in arginine synthesis are widely expressed in tissues, but some key enzymes, such as carbamoyl phosphate synthase-1 (CPS-1), ornithine carbamoyltransferase (I degree ), N monoacetylglutamate synthase (NAG), Only restricted to the liver and small intestinal mucosa.
The effect of arginine on immune function
A large number of clinical studies have shown that arginine can improve the immune function of the human body. Some scholars have studied the effect of arginine on the immune function of gastric cancer during surgery, and found that arginine can increase lymphocyte count, CD4 cell count, CD4/CD8 ratio, and the activity of natural killer cells (NK) is significantly improved. Relevant research results at home and abroad have shown that arginine supplementation in different ways has been observed to improve immune function when immunosuppression is caused by surgical trauma, burns, stress and other conditions.