Regulatory status: For research use only, not for use in diagnostic procedures.
Publication (2)
Cdk12 maintains the integrity of adult axons by suppressing actin remodeling
Figure 1. E Actin is more discontinuous in the projections with Hcy treatment. F Actin was enriched in the cell bodies with Hcy treatment. Effect of arginine:lysine and glycine:methionine intake ratios on dyslipidemia and selected biomarkers implicated in cardiovascular disease: A study with hypercholesterolemic rats
Figure 1. Influence of orally supplemented arginine and glycine on the concentrations of homocysteine and NO in plasma of hypercholesterolemic rats. | Product Name | Cat. No. | Applications | Host Species | Datasheet | Price | Add to Basket |
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Homocysteine (Hcy) is a metabolic intermediate produced by the in vivo demethylation of methionine (Met), which is not present in dietary proteins and does not have to be synthesized endogenously with them. As a sulfhydryl-containing amino acid, Hcy is physiologically essential for processes such as cell cycle progression and maintenance of cellular homeostasis. Hcy metabolism contributes to folate-dependent/folate-independent remethylation to form Met as well as to cysteine formation via the transsulfuration pathway, both of which require vitamin-derived cofactors; vitamin B6 is involved in cysteine synthesis, and vitamins B9, B12, and B2 are involved in the Met synthesis cycle. S-adenosylmethionine (SAM) is a metastable inhibitor of the methylenetetrahydrofolate reductase (MTHFR) reaction and an activator of cystathionine β-synthase (CBS). In the presence of sufficient Met, Hcy produces cysteine via cystathionine β-synthase. In the absence of Met, Hcy undergoes remethylation via N5, N10-methylenetetrahydrofolate reductase to rescue Met. Although Hcy is not directly involved in protein synthesis, its specific functions in folate metabolism and choline catabolism are critical in regulating the effectiveness and function of Met.
Figure 1. Hcy metabolism
(Source: Koklesova L, et al. 2021)
Fluctuations in Hcy levels are associated with a wide range of diseases, making Hcy a potent marker of impaired amino acid and protein homeostasis. Four forms of Hcy are present in plasma: the free thiol form (1%), bound to plasma proteins maintaining disulfide bonds (70-80%), bound to other Hcy to form dimeric Hcy, and bound to other thiols (20-30%). The optimal total Hcy concentration (tHcy) in plasma of healthy individuals ranges from 5.0-15.0 μmol/L (high-performance liquid chromatography) or 5.0-12.0 μmol/L (immunoassay). When plasma levels of Hcy exceed the normal concentration range, the patient suffers from hyperhomocysteinemia (HHcy), and a number of risk factors, such as aging, smoking, and oxidative stress, contribute to the severity of HHcy, which can lead to serious conditions, including neurodegenerative diseases, thrombosis, cerebrovascular disease, and cardiovascular disease. Hypohomocysteinemia occurs when plasma Hcy levels fall below the normal concentration range, and low Hcy levels are associated with peripheral neuropathy.
Homocysteine ELISA Kit
tHcy ELISA Kit
References
1. Koklesova L, et al. Homocysteine metabolism as the target for predictive medical approach, disease prevention, prognosis, and treatments tailored to the person. EPMA J. 2021 Nov 11;12(4):477-505
2. Azzini E, et al. Homocysteine: Its Possible Emerging Role in At-Risk Population Groups. Int J Mol Sci. 2020 Feb 20;21(4):1421.
Q: Based on the preliminary HPLC data, the predicted values for hyperhomocysteinemic plasma (EDTA) are ~25µM in both species, while normal plasma total homocysteine values for rat and mouse are ~5-9µM. According to the manual on the website, for a 1/dilution ratio, the "amount" in human plasma is ~6-7µM, while rat is ~14 µM and mouse is ~5µM. The values in rat plasma are extremely high - does this mean that the "amount" reflects the total concentration in rat and a 1/2 dilution of the other species, or does the kit give better results for some species than others?
A: We speculate that the reasons for this difference may be the following two points:
1. There are differences in the measured values of experimental methods on different platforms. Due to the different detection principles, the quantitative results will be different. This may lead to deviations in the results reported by the same sample under different methods.
2. There are differences in samples. The above data are experimental data obtained by testing limited samples. It represents the typical observations of the kit under specific conditions, but it cannot be completely equivalent to or predict the absolute physiological concentration range of all animal individuals or groups. Individual differences, strains, breeding conditions and other factors may affect the actual measured values.
Combining the above factors, we believe that the effect of the hyperhomocysteinemia model can be more effectively evaluated by controlling variables and focusing on relative changes. The comparability of the absolute concentration values of a single sample between different methods or platforms is relatively limited, while the difference trend between treatment groups usually has higher reliability and biological significance.
Association of methylenetetrahydrofolate reductase C677T gene polymorphism and polycystic ovary syndrome in the South Indian cohort
INDIAN JOURNAL OF EXPERIMENTAL BIOLOGY
Authors: Sekar, Nishu; Samak, Radhika; Patil, Shreya; Ghorpade, Neha; Abilash, Valsala Gopalakrishnan
Vitamin B-12, Folate and Cognitive Function in Older Adults from Southern Brazil
AGEING INTERNATIONAL
Authors: Franca, Vivian Francielle; Barbosa, Aline Rodrigues; d'Orsi, Eleonora
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