Antioxidants capability of plasma

TRAP, Total peroxyl-radical-trapping antioxidant capability of plasma TEAC, Trolox equivalent antioxidant capacity FRAP, ferric-reducing activity of plasma ORAC, oxygen-radical-absorbing capacity PCA, perchloric acid-soluble fraction ABAP, 2,2 -azobis(2-amidoproane). 

TRAP, Total peroxyl-radical-trapping antioxidant capability of plasma. 

Wayner, D., Burton, G., Ingold, K.U. and Locke, S. (1985). Quantitative measurement of total peroxyl radical trapping antioxidant capability of human blood plasma by controlled peroxidation. FEBS Lett. 187, 33-37. 

Long-term administration (between 12 and 36 months) of vitamin C and E alone or in combination at respective daily dosages of 500 and 182 mg (as RRRA acetate) were not capable of modifying the antioxidant capacity of plasma (94),... 

Another example is the tissues that are particularly rich in vitamin C, for example, the cortex of the suprarenal gland or the lens here, vitamin C fulfills both antioxidative functions and metabolic ones as it helps in the formation of collagen structures. Approximately 40% of the body s ascorbate is stored in skeletal muscle because this tissue is relatively abundant and its cellular concentration is tenfold higher than the plasma level. Similarly, the intracellular ascorbate concentration in the brain (3 mM) greatly exceeds the level in the extracellular fluid (200-400 zM). The majority of ascorbate is stored in the astroglial cells that are capable of reducing great quantities of DHAA to ascorbate, which then becomes available for release back into the extracellular fluid. 

Many investigators have attempted to demonstrate increases in plasma antioxidant capability following the consumption of foods, beverages, or supplements rich in PPT. Table 6.5 summarizes the outcomes of 37 such The test substances in-... 

The oxidants responsible for initiating LDL oxidation have been under intense investigation, and several possible mechanisms have been suggested. For example, Oj has been implicated as a major contributor to LDL oxidation mediated by macrophages and smooth muscle cells (H8). Here, O " is converted to H2O2 by SOD, which in turn is acted upon by a transition metal ion with the formation of HO. Another possible role for Cff is its reaction with NO to form ONOCT, which is capable of oxidizing lipids and sulfhydryl groups, even in the presence of plasma antioxidants (VI). Moreover, in vitro studies have shown that ONOCT can induce the formation of F2-isoprostanes, nonenzymatic products of the free radical-catalyzed oxidation of arachidonic acid (M13). 

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