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 Posted: Sat Oct 04, 2008 12:15 am Post subject: Effect of flavin compounds on glutathione reductase activity |
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J Clin Invest. 1969 Oct;48(10):1957-66. Links
Effect of flavin compounds on glutathione reductase activity: in vivo
and in vitro studies.Beutler E.
Increases or decreases of red cell glutathione reductase (GR) have
been described in connection with many clinical abnormalities. We find
that GR activity as measured in hemolysates represents only a portion
of the available GR activity. The addition of small amounts of flavin
adenine dinucleotide (FAD), but not of flavin mononucleotide or
riboflavin, activates the GR of hemolysates. 1 muM FAD results in a
maximal activation within 10 min; gradually increasing activation
occurs at much lower, for example, 20 mmuM FAD concentrations. Once
FAD has activated GR, dilution or dialysis does not reverse activation
of the enzyme. Activation of GR by FAD can be inhibited by adenosine
triphosphate (ATP), and to a lesser extent by adenosine diphosphate
(ADP) and adenosine monophosphate (AMP), if these adenine nucleotides
are added before the addition of FAD, but only to a slight extent if
FAD is added before the adenine nucleotides. The addition of FAD to GR
does not alter its electrophoretic mobility but produces
intensification of the bands.The administration of 5 mg of riboflavin
daily produces marked stimulation of red cell GR activity within only
2 days. After cessation of riboflavin administration, the GR activity
again begins to fall. The degree of stimulation of GR activity by
riboflavin is inversely correlated with the level of dietary
riboflavin intake. The base line GR activity of normal individuals is
directly correlated with the level of dietary riboflavin intake. The
previously unexplained variations of glutathione reductase in health
and disease must be reevaluated in light of the state of riboflavin
nutrition and metabolism of the subject.
PMID: 5822598 [PubMed - indexed for MEDLINE]
PMCID: PMC322432 |
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