Ascorbic acid donates electrons to dopamine beta-monooxygenase during the hydroxylation of dopamine to norepinephrine in vitro. However, the possible role of ascorbic acid in norepinephrine biosynthesis in vivo has not been defined. We therefore investigated the effect of newly accumulated ascorbic acid on catecholamine biosynthesis in cultured bovine adrenal chromaffin cells. Cells supplemente...

CONTEXT Some animal studies suggest that orally administered ascorbic acid may chelate lead and decrease the risk of the toxic effects of lead. However, results from several small studies in humans have yielded inconclusive evidence of a beneficial effect of ascorbic acid on lead toxicity. OBJECTIVE To examine the relationship between serum ascorbic acid levels and prevalence of elevated bloo...

There have been numerous reports suggesting that the metabolism of ascorbic acid in humans and in animals is affected by stress.l However, detailed information which would permit an analysis of the underlying mechanism is not available. From the variety of effects cited, it would appear that no single mechanism can explain all of the findings. It has been suggested that increased ascorbic acid ...

In this study, a new reaction system for quantitative determination of ascorbic acid was introduced. The developed method is based on inhibitory effect of ascorbic acid on the Orange G-bromate system. The change in absorbance was followed spectrophotometrically at 478 nm. The dependence of sensitivity on the reaction variables including reagents concentration, temperature and time was investiga...

Various chemicals can have different effects on the properties of the cement slurry. In this paper, the different effects of L-ascorbic acid have been investigated on the important parameters of cement slurry made from class G oil well cement. These parameters included the amount of free fluid, rheological properties, Thickening Time, and compressive strength. Several cement slurries were made ...

The H-point standard addition method was applied to kinetic data for simultaneous determination of citric and ascorbic acid or selective determination of ascorbic acid in presence of citric acid. The method is based on the difference in the rate of reaction of citric and ascorbic acid with copper(II)-ammonia complex. The linear dynamic ranges for the two analytes of citric and ascorbic acid are...

The inhibitory effect of ascorbic acid on Campylobacter jejuni is described. In vitro growth of clinical strains, as measured spectrophotometrically, was inhibited by 0.5 mg of freshly prepared L-ascorbic acid per ml. Alkaline-treated or aged L-ascorbic acid increased inhibition, as did copper; however, L-cysteine, L-cystine, and glutathione prevented inhibition. Biochemical analysis of the med...

in this study, a new reaction system for quantitative determination of ascorbic acid was introduced. the developed method is based on inhibitory effect of ascorbic acid on the orange g-bromate system. the change in absorbance was followed spectrophotometrically at 478 nm. the dependence of sensitivity on the reaction variables including reagents concentration, temperature and time was investiga...

1. No difference in health was observed between men on megadosage of ascorbic acid and controls during the year of an Antarctic expedition. 2. All men appeared to have a satisfactory intake of ascorbic acid throughout the year. 3. There was a statistically significant decrease in excretion of ascorbic acid by men on megadosage over the year, and by the controls. 4. The decline in excretion by t...

In the present study, ascorbic acid weakly inhibited the multiplication of viruses of three different families: herpes simplex virus type 1 (HSV-1), influenza virus type A and poliovirus type 1. Dehydroascorbic acid, an oxidized form of ascorbic acid and hence without reducing ability, showed much stronger antiviral activity than ascorbic acid, indicating that the antiviral activity of ascorbic...