Hepatorenal tyrosinemia/fumarylacetoacetate hydrolase deficiency
William L. Nyhan, Georg F. Hoffmann, Aida I. Al-Aqeel, Bruce A. Barshop in Atlas of Inherited Metabolic Diseases, 2020
Increased quantities are also excreted in the urine. Of the tyrosyl compounds found in the urine, p-hydroxyphenyllactic acid is the most prominent; p-hydroxyphenylpyruvic acid and p-hydroxyphenylacetic acid are also present in appreciable quantities. Patients often have elevated concentrations of methionine in the blood. Hypoglycemia is common, especially in the acute illness. In chronic cirrhosis or after treatment, tyrosine concentrations may be normal. On the other hand, during the acute stages of hepatocellular damage many other amino acids may be found in elevated amounts in the serum, including cystathionine, proline and hydroxyproline. These patterns, along with the tyrosine, are reflected in the urinary excretion of amino acids. They are superimposed on the generalized aminoaciduria that results from the renal tubular aspects of the disease. Patients also have phosphaturia and hypophosphatemia. The presence of reducing substance completes the picture of the renal Fanconi syndrome. The sugar is usually glucose, but other sugars have been reported [4, 68]. With progression, there is systemic acidosis, increased potassium loss, and hypokalemia.
Toward Clinical Pharmacologic Otoprotection
Stavros Hatzopoulos, Andrea Ciorba, Mark Krumm in Advances in Audiology and Hearing Science, 2020
Methionine is an important amino acid typically obtained from protein sources such as meats, dairy products, and beans, nuts and seeds. Methionine promotes the re-synthesis of glutathione (GSH) in response to GSH depletion (Morris et al., 2014) and serves as an antioxidant (Kim et al., 2014; Morris et al., 2014). Like most nutritionally important amino acids, D-methionine (D-Met), and L-methionine (L-Met) are mirror images, termed enantiomers, and they differ based on the presence of one asymmetric carbon atom (Friedman, 1999). Like other protein-associated D-amino acids, the D-Met enantiomer is more poorly absorbed than the L-isomer (Friedman and Levin, 2012; Zhang et al., 2015). D-isomers may, therefore, be better candidates for delivery in fortified foods (Friedman and Levin, 2012).
Inflammation
George Feuer, Felix A. de la Iglesia in Molecular Biochemistry of Human Disease, 2020
Experimental studies have shown that the healing process of surface wounds is markedly prolonged by protein deficiency, and the deficiency can be reversed by the administration of DL-methionine.499 In patients DL-methionine is also effective, whereas other amino acids, lysine, valine, or tryptophane do not exert similar effects to methionine despite that lysine represents an important constituent of collagen. Although there is a greater nitrogen retention when methionine is fed, the protein sulfur is more important than protein nitrogen in the promotion of wound healing. In protein-deficient animals, there is a lack of mucopolysaccharides and impaired collagen production in wounds; methionine restores the synthesis of both compounds. When methionine and vitamin C are given together they are more effective than either compound given alone. Lysine deficiency exerts only a moderate effect on wound healing.245 In this case the epithelial regeneration is prompt, and there is no difference in mucopolysaccharide synthesis. Lysine deficiency reduces the ability of fibroblasts to synthesize proteins. Moreover, the structure of fibroblasts is modified in lysine deficient animals, resulting in decreased production of collagen precursors and mature collagen, and as a result, the scar becomes porous.
Interference of altered plasma trace elements profile with hyperhomocysteinemia and oxidative stress damage to insulin secretion dysfunction in Psammomys obesus: focus on the selenium
Published in Archives of Physiology and Biochemistry, 2023
Asma Bouazza, Eric Fontaine, Xavier Leverve, Elhadj-Ahmed Koceir
The first point is linked to the plasma hCys homocysteine accretion can either due to its excessive production or is poorly degraded. The link between hCys and diet becomes important to elucidate, essentially the presence of methionine in diet. The laboratory chow diet (LCD) contains 25% of proteins compared to 3.53% in the natural diet (ND) represented by halophilic plants (Marquie et al. 1984). These Chenopodiaceae contain little methionine (Frenkel et al.1972); compared to the LCD, which is very high (0.010 versus 0.50%, respectively). In LCD, methionine is found in wheat, oat flour, meat, fish, and milk powder proteins. This difference between methionine amounts in ND compared to LCD explains the HhCys in experimental groups II, III, and IV (under LCD) versus control group I (under ND). Thus, in P. obesus model, the LCD (high caloric diet) leads to the abnormal elevated hCys production which becomes toxic for β-cells (Scullion et al. 2016).
Hyperhomocysteinemia in men and women of married couples with reproductive disorders. What is the difference?
Published in Systems Biology in Reproductive Medicine, 2023
Zoia Rossokha, Liliya Fishchuk, Liudmyla Vorobei, Nataliia Medvedieva, Olena Popova, Viktoriia Vershyhora, Larysa Sheyko, Ljudmila Brisevac, Dmytro Stroy, Nataliia Gorovenko
Hyperhomocysteinemia (HHcy, E72.1) is an autosomal recessive inherited metabolic disease caused by variations (mutations) in folate metabolism genes, characterized by impaired methionine metabolism and accumulation of homocysteine (Hcy) in the blood serum. Homocysteine is an essential, sulfur-containing, non-proteinogenic amino acid formed during the metabolism of methionine and cysteine. In vitro, high levels of Hcy have been shown to cause oxidative damage and endothelial dysfunction, with increased platelet adhesion, deposition of low-density lipoproteins in the arterial wall, activation of the coagulation cascade, disruption of the normal balance of redox reactions (Eldibany and Caprini 2007). HHcy can directly disrupt DNA methylation processes, leading to altered gene expression (Zhou et al. 2014).
Tadalafil ameliorates memory deficits, oxidative stress, endothelial dysfunction and neuropathological changes in rat model of hyperhomocysteinemia induced vascular dementia
Published in International Journal of Neuroscience, 2022
Administration of l-Methionine produced a significant increase in serum homocysteine levels and a decrease in body weight when compared to naïve rats. Tadalafil low dose (5 mg/kg/day, p.o.), Tadalafil high dose (10 mg/kg/day, p.o.) and Donepezil (0.5 mg/kg/day, i.p.) did not show any significant effect on l-Methionine-induced increase in serum homocysteine levels (Table 1). However, drug treatment (Tadalafil 5 mg/kg/day; 10 mg/kg/day, p.o.) and Donepezil (0.5 mg/kg/day, i.p.) tried to restore l-Methionine induced decrease in body weight in a significant manner as compared to l-Methionine group rats. Furthermore, vehicle (sodium carboxymethyl cellulose) group and the drug (Tadalafil; Donepezil) per se group did not show any significant effect on serum homocysteine levels and body weigh in comparison to the naive group animals (Table 1).
Related Knowledge Centers
- Angiogenesis
- Biosynthesis
- Cysteine
- Essential Amino Acid
- Genetic Code
- Protein
- Taurine
- Amino Acid
- Glutathione
- S-Adenosyl Methionine