Abstract :

Tryptophan is an essential amino acid found in many protein-based foods and dietary proteins including meats, dairy, fruits, and seeds. High-glycaemic index and -glycaemic load meals also increase the availability of tryptophan. The main objective of the study is to find the role of tryptophan in diabetic patients. Tryptophan metabolism has been reported highly associated with insulin resistance and diabetes risk. The activity of rate-limiting enzyme of tryptophan-kynurenine, indoleamine-2,3-dioxygenase (IDO), was enhanced significantly in T2D patients, thus downstream metabolites such as kynurenine, kynurenic acid, xanthurenic acid and hydroxykynurenine, were higher in T2D than in non-diabetic subjects, although inconsistent observations of tryptophan levels. Returning to the question posed at the beginning of the review, these studies have shown that decreased level of tryptophan plays an important role in diabetic patients. decrease in plasma TRP levels in diabetic patients regardless of their gender and these patients also exhibited a greater incidence of memory dysfunction compared to the controls.

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Keywords :

DM, Level, Plasma, Tryptophan

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References :

1. Haider S, Khaliq S, Haleem DJ (2007). Enhanced serotonergic neurotransmission in the hippocampus following tryptophan administration improves learning acquisition and memory consolidation in rats. Pharmacol Rep; 59: 53-7.
2. Bloomgarden Z (2018). Diabetes and branched-chain amino acids: What is the link? J Diabetes.;10(5):350-352. doi: 10.1111/1753-0407.12645. Epub 2018 Feb 13. PMID: 29369529.
3. McCormack, S. E., Shaham, O., McCarthy, M. A., Deik, A. A., Wang, T. J., Gerszten, R. E., Clish, C. B., Mootha, V. K., Grinspoon, S. K., & Fleischman, A. (2013). Circulating branched-chain amino acid concentrations are associated with obesity and future insulin resistance in children and adolescents. Pediatric obesity, 8(1), 52–61. https://doi.org/10.1111/j.2047-6310.2012.00087.x
4. Park S, Park JY, Lee JH, Kim SH (2015). Plasma levels of lysine, tyrosine, and valine during pregnancy are independent risk factors of insulin resistance and gestational diabetes. Metab Syndr Relat Disord;13(2):64-70. doi: 10.1089/met.2014.0113.
5. Chou, M.Y., Lin, C.H., Chao, P.L., Hung, J.C., Cruz, S.A., Hwang, P.P. (2015) Stanniocalcin-1 Controls Ion Regulation Functions of Ion-transporting Epithelium Other than Calcium Balance. International journal of biological sciences. 11:122-32.