Immunonutrients are found in both macro and micro nutrients, such as nucleotides, glutamine, arginine, cysteine and taurine in amino acids, monounsaturated fatty acids, polyunsaturated fatty acids, short-chain fatty acids, vitamins A, C, E and? Carotene and trace elements such as zinc and selenium are important immunomodulators. The amount of these nutrients supplied to patients should be more than the amount needed by the general population. But in any case, these immune nutrients should meet the metabolic and immune needs of the body at the same time. Glutamine is a star nutrient in the 20th century, and a large number of research papers involve glutamine. According to incomplete statistics, there were 10265 scientific papers related to glutamine during 10265, of which 726 were about nutrition research, 3 12 were about metabolism, and 242 were about parenteral nutrition evaluation of glutamine.
At the end of the 20th century 10, glutamine was considered as conditionally essential amino acid, which was an ideal energy source for lymphocytes, hepatocytes and intestinal mucosal cells. The low concentration of glutamine in body fluids, especially cells, suggests that glutamine deficiency during stress is related to complications and increased mortality. Adding glutamine to severe patients can reduce complications and mortality. Tyrosine and cysteine can be synthesized from essential amino acids of healthy adults, so they are non-essential amino acids. However, when adults suffer from liver and kidney diseases, premature infants and newborns, the activities of various enzymes that synthesize tyrosine and cysteine decrease, and tyrosine and cysteine become conditionally essential amino acids. Therefore, attention should be paid to clinical nutritional therapy. This problem did not attract enough attention and attention in the 20th century.
A balanced diet with sufficient protein and proper amino acid ratio is very important for maintaining the anabolism of the body in critically ill patients. However, due to the solubility and instability of glutamine, tyrosine and cysteine, taurine can not be effectively utilized due to the gradient difference inside and outside the cell, so it is difficult to ensure a reasonable balanced diet. Because of its stability and high solubility, dipeptide products have been used in clinic, and now there are adducts containing glutamine, tyrosine, cysteine and taurine, which will be solved in this century.
The synthesis of glutathione is very important for patients with severe clinical symptoms. The ratio of reduced glutathione to oxidized glutathione in tissues decreased, suggesting that the body is in an oxidative stress state, and the low glutathione concentration is often accompanied by a significant decrease in glutamine concentration in tissues. Recent studies have shown that adding glutamine can increase the storage of glutathione in liver and intestine. Its biochemical basis is that glutamine-acid, the precursor of glutathione, is difficult to pass through the cell membrane, but glutamine can enter and leave the cell membrane freely, so glutamine becomes the precursor of glutamic acid after deamination.
Glutamine can also weaken the transmitter of inflammatory factors and up-regulate the source of anti-inflammatory factors, thus affecting endogenous inflammatory response. Studies have shown that glutamine dipeptide can reduce the synthesis and cytotoxicity of tumor necrosis factor and IL-8, and increase the expression ability of anti-inflammatory factor IL- 10. Propamide-glutamine can promote the synthesis of cysteinyl-leukotriene, and the ability of the body to synthesize cysteinyl-leukotriene is closely related to the prognosis, which is a survival biochemical index to predict the prognosis of severe patients.
It is suggested that glutamine is also the key factor of glucose intolerance. In hyperinsulinemia, glutamine inactivates the effect of insulin on glucose formation and increases the utilization of insulin-regulated glucose. Therefore, in the case of insulin resistance such as diabetes, sepsis and septicemia, glutamine dipeptide can play an active role as a nutritional adjuvant.
Glutamine dipeptide may also be a cardiovascular protective factor. Glutamine dipeptide can maintain the concentration of glutamine and high-energy phosphate in cardiovascular system and prevent the accumulation of lactic acid. So as to support cardiac reperfusion during embolization.
At present, tyrosine dipeptide with high solubility has been obtained, which can meet the clinical demand for tyrosine. In acute and chronic renal failure, the abnormal amino acid metabolism can be corrected by supplementing glycine, tyrosine, dipeptide and serine, increasing histidine and valine at the same time and reducing phenylalanine content. In acute and chronic liver insufficiency, the degradation and hydrolysis of glycine-tyrosine dipeptide and propylamine-tyrosine dipeptide are not affected, so parenteral supply of glycine-tyrosine dipeptide and propylamine-tyrosine dipeptide can be used as the source of tyrosine in liver disease. 2 1 century, people also applied tyrosine dipeptide to premature infants and newborns. When people are infected with HIV, free radicals can induce the release of tumor necrosis factor, and sulfur-containing antioxidants can inhibit this reaction. Cysteine is a potential antioxidant, which can inhibit this reaction and the expression of transcription factors in stimulated T cells.
Because transcription factors increase the expression of HIVmRNA, cysteine may play a role in the treatment of immunodeficiency syndrome. Due to the lack of adequate preparation,
Due to oxidative stress, the content of antioxidants is decreasing during metabolism. Therefore, delivering enough antioxidants can resist the influence of oxygen free radicals and their subsequent damage to the body. Antioxidants, such as vitamin E, vitamin C and carotene, cooperate with each other. Vitamin c can remove a wide range of oxides and regenerate vitamin e. Antioxidants cooperate with antioxidants to ensure that the body is in a good functional state. Therefore, it is much better to give patients an "antioxidant cocktail" than to take a large dose of antioxidants. The recommended supply ratio is: vitamin E: vitamin C: carotene = 1: 2: 0. 1.