We studied the acquisition of dehydroascorbic acid by rat hepatocytes, H4IIE rat hepatoma cells and Xenopus laevis oocytes. Transport kinetics and competition and inhibition studies revealed that rat hepatocytes transport oxidized dehydroascorbic acid through a single functional component possessing the functional and kinetic properties expected for the glucose transporter GLUT2. On the other hand, rat hepatoma cells showed expression of at least two dehydroascorbic acid transporters with the expected functional and kinetic properties expected for GLUT1 and GLUT2. Expression studies of GLUT2 in X. laevis oocytes followed by transport kinetics and competition and inhibition studies revealed that GLUT2 is a low affinity dehydroascorbic transporter whose kinetic and functional properties match those observed for the endogenous GLUT2 transporter in rat hepatocytes and rat hepatoma cells. Therefore, GLUT2, a transporter known as a low affinity transporter of glucose and fructose and a high affinity transporter of glucosamine is also a low affinity dehydroascorbic acid transporter.
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http://dx.doi.org/10.1016/j.bbrc.2011.05.070 | DOI Listing |
Int J Mol Sci
December 2024
Engineering Research Center for Fruit Crops of Guizhou Province, Engineering Technology Research Centre for Rosa Roxburghii of National Forestry and Grassland Adminstratio, College of Agriculture, Guizhou University, Guiyang 550025, China.
fruit has a short postharvest shelf life, with rapid declines in quality and antioxidant capacity. This research assessed how phytic acid affects the antioxidant capacity and quality of fruit while in the postharvest storage period and reveals its potential mechanism of action. The findings suggested that phytic acid treatment inhibits the production of malondialdehyde (MDA) and enhances the activities and expressions of glutathione peroxidase (GPX), peroxidase (POD), catalase (CAT), and superoxide dismutase (SOD) while decreasing the generation of superoxide anions (O) and hydrogen peroxide (HO).
View Article and Find Full Text PDFChemistry
January 2025
Beijing Normal University, Chemistry, CHINA.
Though nanozymes are becoming promising alternatives to natural enzymes due to their superior properties, constructing nanozyme with high specificity is still a great challenge. Herein, with Cu2+ as an active site and adenine as a ligand, Adenine-Cu-PO4 is synthesized in phosphate-buffered saline. As an oxidase mimic, Adenine-Cu-PO4 could selectively catalyze oxidation of ascorbic acid (AA) to dehydroascorbic acid, but not universal substrates (3,3',5,5'-tetramethylbenzidine (TMB), 2,2'-azino-bis (3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) and 2,4-dichlorophenol (2,4-DP)), small biomolecules (dopamine, glutathione, glucose, galactose), other vitamins (vitamin A acid, vitamin B1, vitamin K1) and even dithiothreitol (a common interference of AA).
View Article and Find Full Text PDFBiochim Biophys Acta Gen Subj
February 2025
Program in Biological System Sciences Graduate School of Comprehensive Scientific Research, Prefectural University of Hiroshima, 5562, Nanatsuka, Shobara, Hiroshima 727-0023, Japan.
Anticancer effects of high-dose vitamin C (VC) have been evaluated on many cancer cell lines, and its efficacy in clinical trials and in combination with anticancer drugs or radiation have been reported; however, its effect on gastric cancer and its mechanisms remain unclear. In the present study, the cell growth inhibitory/lethal effects of high-dose ascorbic acid (AsA), a reduced form of VC was examined on three gastric cancer cell lines. Of these, signet ring cell carcinoma NUGC-4 cells were the most sensitive, but the effects were small and limited in normal cells.
View Article and Find Full Text PDFPhotosynthetica
July 2024
Henan Institute of Science and Technology, 453003 Xinxiang, China.
Cadmium stress (CS) induced the peroxide damage and inhibited wheat photosynthetic capacity and growth. Compared to CS, selenium (Se) application plus CS bolstered chlorophyll and carotenoid contents, photosynthetic rate, the maximum photochemical efficiency of PSII, the quantum yield of PSII photochemistry, and photochemical quenching, superoxide dismutase, catalase, ascorbate peroxidase, glutathione reductase, L-galactono-1,4-lactone dehydrogenase, and gamma-glutamylcysteine synthetase activities, ascorbic acid and glutathione contents, AsA/dehydroascorbic acid and GSH/oxidized glutathione, and decreased nonphotochemical quenching (q), antioxidant biomarkers malondialdehyde and hydrogen peroxide contents, and electrolyte leakage (EL). At the same time, Se alone declined antioxidant biomarkers contents, q and EL, and augmented the rest of the aforementioned indexes.
View Article and Find Full Text PDFEmerg Microbes Infect
December 2025
National Research Center for Protozoan Diseases, Obihiro University of Agriculture and Veterinary Medicine, Obihiro, Japan.
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