The stromal cell line ST2, derived from mouse bone marrow, differentiated into osteoblast-like cells in response to ascorbic acid. Ascorbic acid induced alkaline phosphatase (ALPase) activity, the expression of mRNAs for proteins that are markers of osteoblastic differentiation, the deposition of calcium, and the formation of mineralized nodules by ST2 cells. We investigated the mechanism where...

IT is now accepted that the repair of collagenous tissue depends on an adequate intake of ascorbic acid (Hojer, 1924; Wolbach and Howe, 1926). Bourne (1942a) has fully reviewed the experimental work. The relation of local ascorbic acid concentration to collagenous tissue healing, however, has not been so fully investigated. Some disagreement is apparent when the effect of the addition of ascorb...

After numerous negative experiments on the possible effect of thyroxine on oxidations in animal tissue slices and homogenates, experiments were tried with this hormone on a vegetable enzyme, ascorbic acid oxidase. It was found that small amounts of thyroxine stimulated the oxygen uptake of the ascorbic acid-ascorbic acid oxidase system. Since ascorbic acid oxidase is a copper protein (I), the e...

The platelet ascorbic acid concentration was measured in 26 normal subjects and found to be 20 times as high as in plasma. This is in agreement with previous reports in the literature. The platelets of patients with uraemia, leukaemia, and megaloblastic anaemia had a lower than normal platelet ascorbic acid content. In uraemia and megaloblastic anaemia the plasma ascorbic acid concentration was...

Human tumors may contain high concentrations of ascorbic acid, but little is known about how they acquire the vitamin. Certain specialized cells can transport ascorbic acid directly through a sodium ascorbate cotransporter, but in most cells, vitamin C enters through the facilitative glucose transporters (GLUTs) in the form of dehydroascorbic acid, which is then reduced intracellularly and reta...

Oxidative stress is implicated in the cognitive deterioration associated with normal aging as well as neurodegenerative disorders such as Alzheimer's and Parkinson's diseases. We investigated the effect of ascorbic acid (vitamin C) on oxidative stress, cognition, and motor abilities in mice null for gulono-gamma-lactone oxidase (Gulo). Gulo-/- mice are unable to synthesize ascorbic acid and dep...

Ascorbic acid enhances NO bioactivity in patients with vascular disease through unclear mechanism(s). We investigated the role of intracellular ascorbic acid in endothelium-derived NO bioactivity. Incubation of porcine aortic endothelial cells (PAECs) with ascorbic acid produced time- and dose-dependent intracellular ascorbic acid accumulation that enhanced NO bioactivity by 70% measured as A23...

During the period of a low vitamin C intake (approximately equal to 20 mg per day) ascorbic acid in a dose of 2 x 500 mg per day was administered to 82 men and women aged 50-75 years. A correlation of plasma cholesterol levels determined before and after a three months' administration of ascorbic acid showed the effect of vitamin C to be dependent on the starting concentration of plasma cholest...

The efficacy of ascorbic acid therapy in Chediak-Higashi syndrome (CHS) was assessed in two humans and in the mouse model of this disease. Ascorbic acid (6 g/day) was given for 8 mo to two brothers (26 and 27 yr old) with CHS. The therapy had no effect on the clinical course of these patients and no change in their complete blood count or abnormal leukocyte morphology (giant lysosomes). In addi...

BACKGROUND L-ascorbic acid is an essential part of the human diet and has been associated with a wide range of chronic complex diseases, including cardiovascular outcomes. To date, there are no confirmed genetic correlates of circulating concentrations of L-ascorbic acid. OBJECTIVE We aimed to confirm the existence of an association between common variation at the SLC23A1 gene locus and circu...