LYCOS RETRIEVER 
Vitamin C: Antioxidants
built 270 days ago
Ascorbate (reduced vitamin C) is an important enzyme cofactor, neuromodulator, and antioxidant that is stored at millimolar concentrations in the cytosol of cerebral astrocytes. Because these cells swell during hyponatremia, cerebral ischemia,sport of ascorbate. Ascorbate efflux from primary cultures of rat astrocytes was rapidly (within 1 min) increased by incubation in hypotonic medium. Efflux ... increased when astrocytes, which had been adapted to a hypertonic environment, were swollen by transfer to isotonic medium. Swelling-induced ascorbates efflux was inhibited by the anion-transport inhibitors 4,4'-diisothiocyanostilbene-2,2 '-disulfonic acid (DIDS) and 4,4'-dinitrostilbene-2,2'-disulfonic acid (DNDS). The pathway that mediates ascorbate efflux was found to be selective because a larger anion, 2',7'-bis(carboxyethyl)-5-(or -6)-carboxyfluorescein (BCECF), was retained in the swollen astrocytes.
Source:
Vitamin C (ascorbic acid) is a water-soluble antioxidant that is responsible for maintaining iron in its reduced state ... preserving activity of the hundreds of enzymes that contain iron at the catalytic site. The most well-documented of these enzymes are the iron-containing prolyl and lysyl hydroxylases that catalyze the post-translational hydroxylation of proline and lysine. Hydroxyproline and hydroxylysine provide sites for cross-linking of collagen fibrils responsible for tensile strength and elasticity in connective tissue. Tissues most sensitive to Vitamin C status are those which contain large amounts of collagen such as blood vessels and capillaries, bone, and scar tissue. Vitamin C dependent reactions cover a broad range of functions that include phagocytic activity, neurotransmitter synthesis, and hepatic production of bile from cholesterol.
Source:
The potential of vitamin C, an antioxidant, to protect the radiosensitive spermatogonial cells in mouse testes against the effects of chronic irradiation by radionuclides incorporated into tissue was investigated. Interestingly, when injected intratesticularly, a small and nontoxic amount of vitamin C (1.5 microg in 3 microl saline) protected the spermatogonia against the damage associated with high-LET radiation caused by Auger electrons from similarly administered 5-(125I)-iodo-2'-deoxyuridine (125IdU). A dose modification factor (DMF) of 2.3 was obtained. In contrast, no protection was observed when 210Po, an alpha-particle emitter, was administered similarly. These findings suggest that the mechanism of action of the Auger effect is of an indirect nature, which is in contrast to the direct action generally believed to be responsible for biological damage caused by high-LET radiations.
Source:
Vitamin C is an antioxidant that is required for tissue growth and repair, adrenal gland function, and healthy gums. It protects against the harmful effects of pollution, prevents cancer, protects against infection, and enhances immunity. It ... may reduce cholesterol levels and high blood pressure, and prevent atherosclerosis. Essential in the formation of collagen, vitamin C protects against blood clotting and bruising, and promotes the healing of wounds and the production of anitstress hormones. It also aids in the interferon production, and is needed for the metabolism of folic acid, tyrosine, and phenylalanine.
Source:
Vitamin C is a water-soluble antioxidant and can quench both reactive oxygen species and reactive nitrogen species. This antioxidant activity diminishes lipid peroxidation, oxidative DNA damage and oxidative protein damage. Oxidation of low density lipoprotein (LDL) has been suggested to be a factor causing atherosclerosis. Vitamin C prevents LDL from being oxidized. Vitamin C increases high density lipoprotein (HDL) cholesterol, probably resulting in decreased risk of atherosclerosis.
Source:
Depressed vitamin C levels can ultimately cause decreased performance. Vitamin C can regenerate other antioxidants and act as an antioxidant itself. Therefore the need for vitamin C is likely increased in those who exercise regularly. An intake of 100 to 500 mg seems to be sufficient to meet the needs of the exercising individual. This level can easily be obtained through a fruit and vegetable inclusive diet. As stated earlier these dosages would best be absorbed if taken in small quantities at multiple intervals.
Source:
MORE ABOUT
Antioxidants