A ‘dehydroascorbic acid reductase’ factor in guinea-pig tissues

Grimble, Robert F.; Hughes, R. E.

doi:10.1007/bf02144516

Cited by 32 publications

(4 citation statements)

References 8 publications

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“…Thus both ascorbic acid and is0 ascorbic acid are substrates for the plant enzyme ascorbic acid oxidase (Long, 1961). Again, plant DHAA reductase is active towards both DHAA and DHisoAA, as too is the 'DHAA-reductase' system recently described for animal tissues (Hughes, 1964;Grimble and Hughes, 1967).…”

Section: Discussionmentioning

confidence: 73%

The Passage of Vitamin C across the Erythrocyte Membrane

Hughes

Maton

1968

Br J Haematol

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Summary In all the species examined dehydroascorbic acid entered the erythrocyte considerably more rapidly than ascorbic acid (vitamin C). The uptake was pH‐dependent but did not appear to be influenced by enzyme inhibitors. The rate of uptake of the dehydroascorbic acid appeared to be influenced by the activity of an erythrocyte DHAA‐reducing system. Dehydro‐iso ascorbic acid (dehydro‐d‐araboascorbic acid) entered the erythrocyte considerably less rapidly than DHAA. Ascorbic acid was released from the erythrocyte at a comparatively slow rate.

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Section: Discussionmentioning

confidence: 73%

The Passage of Vitamin C across the Erythrocyte Membrane

Hughes

Maton

1968

Br J Haematol

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“…Early investigators of ascorbic acid metabolism in animal tissues recognized that GSH might reduce dehydro-L-ascorbic acid but did not identify a specific cellular enzyme. The current concept that animal tissues reduce dehydro-L-ascorbic acid by a GSH-dependent enzyme is frequently attributed to a series of short articles published in the 1960s (3)(4)(5). The tissue preparations had been homogenized and dialyzed free of endogenous reducing equivalents; although GSH promoted reduction of dehydro-L-ascorbic acid, no comparative evaluation of the effectiveness of NADPH was made.…”

Section: Discussionmentioning

confidence: 99%

Regeneration of Ascorbic Acid by Rat Colon

Choi¹,

Rose²

1989

Experimental Biology and Medicine

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Plants and animals alike use ascorbic acid in a variety of reactions that result in net generation of dehydro-L-ascorbic acid. The ability to reduce dehydro-L-ascorbic acid back to ascorbic acid would conserve "total ascorbate" and would help to maintain the toxic oxidized form of the molecule at a low level. This study evaluated the rate of dehydro-c-ascorbic acid reduction either by following the rate of NADPH consumption or by analysis of the amount of ''C-labeled dehydro-L-ascorbic acid converted to ascorbic acid. A large percentage of the NADPH consumed by a semipurified preparation of rat colonic mucosa in vitro was dependent on the presence of dehydro-L-ascorbic acid. The tissue factor active in regenerating ascorbic acid is intermediate in size between cytochrome c and blue dextran. The present results indicate that the mucosa reduced dehydrw-ascorbic acid by a cytosolic enzyme that uses NADPH as a hydrogen donor. Subsequent to precipitation by ammonium sulfate, the 5 5 7 0 % fraction contains most of the reductase activity while consisting of only 17% of the cellular soluble protein.

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“…By R. E. HUGHES, Department of Applied Biology, UWIST, Caydzff, Wales Vitamin C is L-xyloascorbic acid (ascorbic acid, AA). Its first oxidation product is dehydroascorbic acid (dehydroAA) which also possesses vitamin C activity, possibly because of the ease with which many animal tissues can reduce it back to AA (Grimble & Hughes, 1967). AA and dehydroAA may be referred to as 'total vitamin C'.…”

Section: Assessment Of Vitamin C Statusmentioning

confidence: 99%