Ochromonas danica Pringsheim, a freshwater chrysomonad, converts d-glucose into l-ascorbic acid over a metabolic pathway that ;inverts' the carbon chain of the sugar. In this respect, l-ascorbic acid formation resembles that found in ascorbic acid-synthesizing animals. It differs from this process in that d-galacturonate and l-galactono-1,4-lactone, rather than d-glucuronate and l-gulono-1,4-la...

BACKGROUND Oxidative stress in teratozoospermic semen samples caused poor assisted reproductive techniques (ART) outcomes. Among antioxidants, ascorbic acid is a naturally occurring free radical scavenger and as such its presence assists various other mechanisms in decreasing numerous disruptive free radical processes. OBJECTIVE The main goal of this study was to evaluate potential protective...

We tested the hypothesis that ascorbic acid in the diet of rats lowers the concentration of soluble Cu in the small intestine, causing a decrease in apparent Cu absorption. Male rats were fed on diets adequate in Cu (5 mg Cu/kg) without or with 10 g ascorbic acid/kg. The diet with ascorbic acid was fed for either 6 or 42 d. Ascorbic acid depressed tissue Cu concentrations after a feeding period...

Ascorbic acid appears to have vasodilatory properties, but the underlying mechanisms are not well understood. The aims of this study were to define the acute effects of locally infused ascorbic acid in human veins and to explore underlying mechanisms by using pharmacological tools in vivo. Ascorbic acid was infused in dorsal hand veins submaximally preconstricted with the alpha(1)-adrenoceptor ...

Leucocyte and plasma ascorbic acid values were measured in healthy students, adult factory employees, and old people not receiving supplementary vitamin C and in healthy old people receiving 500 mg of vitamin C daily. Significant positive correlations between leucocyte and plasma ascorbic acid were found in all the groups. The regression lines differed significantly between one another within t...

Expression of the Na(+)-ascorbate cotransporter, SVCT2, was detected in rat brain and in primary cultures of cerebral astrocytes by Northern blot analysis. SVCT2 expression in cultured astrocytes increased in response to the cyclic AMP analog, dibutyryl cyclic AMP. A mathematical model of ascorbic acid transport was developed to evaluate the hypothesis that Na(+)-ascorbate cotransport across th...

The suppressive effect of L-ascorbic acid on the growth of bone marrow cells from patients with acute nonlymphocytic leukemia was studied using a modified agar culture method featuring daily feeding to allow the growth of leukemic cell colonies. In seven of 28 patients (25%), the numbers of leukemic cell colonies grown in culture were reduced to 21% of control by the addition of L-ascorbic acid...

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...