Beijing Hongvadar Engineering Technology Co.
Beijing Hongvadar Engineering Technology Co.

The Relationship Between Tryptophan and Other Nutrients Metabolism

Tryptophan has a very close relationship with various nutrients such as carbohydrates, proteins, fats, vitamins and trace elements in the process of metabolism.


1. The relationship between tryptophan and carbohydrates


All carbohydrates facilitate entry of L-tryptophan from the gastrointestinal tract into the portal vein. In vitro, starch and disaccharides were found to promote intestinal L-tryptophan transport, but not in monogastric animals. The absorption of fructose is closely related to the concentration of tryptophan in the blood. In patients with fructose malabsorption, the concentration of tryptophan in the blood is very low. Higher intestinal fructose concentrations interfere with L-tryptophan metabolism and reduce the availability of tryptophan for serotonin biosynthesis.


2. Protein and amino acids


The amount of tryptophan directly affects the rate of protein synthesis. When the concentration of tryptophan in the body is high, the speed of protein synthesis is accelerated. On the contrary, when the tryptophan is deficient, the protein synthesis speed will decrease due to the imbalance of amino acids. When dietary protein concentration was different from tryptophan concentration, animal feed intake was also different, and this was accompanied by changes in neurotransmitter concentration. When the diet is rich in tryptophan, the ratio of serum tryptophan to LNAA increases, which can improve the anti-stress ability of stress-sensitive groups. Changes in brain serotonin concentrations caused by tryptophan-containing peptides are very similar to monomeric tryptophan. Brain serotonin and 5-hydroxyindole acetic acid were significantly increased when rats were fed different tryptophan-containing peptides; when tryptophan was orally administered with leucine or its peptides, brain serotonin Concentration drops. In corn and soybean meal-type diets rich in lysine but deficient in tryptophan, when supplemented with tryptophan, body weight gain and feed conversion ratio increased linearly with the increase in supplementation. However, when both tryptophan and lysine were sufficient, and lysine or tryptophan was supplemented, the body weight gain and food intake decreased linearly with the increase of the two supplements. There is an interaction between threonine and tryptophan, and has a significant effect on weight gain and feed conversion ratio.


3. Add tryptophan to fat diet


The addition of tryptophan to the fat diet can reduce the total amount of liver wax, but if it is added to the feed containing aflatoxin, tryptophan will combine with aflatoxin and cause more serious damage to the body. The addition of tryptophan affects fat metabolism, as well as the combined effects of plasma cortisol concentrations and the oxidase system in liver microsomes. The conversion rate from tryptophan to nicotinamide increases with increasing fat intake; the conversion rate decreases when protein intake increases while fat intake increases.


4. The relationship between tryptophan and vitamins


The conversion of tryptophan to niacin was faster when vitamin B6 was included in niacin-deficient diets. Supplementation of tryptophan with niacinamide in the diet significantly improved feed intake, growth and feed conversion. N-methylnicotinamide secretion increases with the addition of nicotinamide. The plasma tryptophan concentration of people infected with HW decreased. Taking nicotinamide orally can increase the plasma tryptophan concentration by 40% and improve the metabolic abnormalities caused by HW.


5. The relationship between tryptophan and minerals


NaCl and KCl can promote the absorption of tryptophan in the intestine, but different ages and different sites in the intestine have different absorption rates. Zn2+ acts on free tryptophan and peptide forms of carriers, protecting them from degradation. However, when the concentration of Zn2+ is too high, it will partially inhibit the absorption of free tryptophan in the small intestine. Tryptophan, as a precursor of pyridine carboxylic acid, promotes the absorption of zinc by animals. Iron deficiency reduces the availability of tryptophan, but has no effect on niacin.

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