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Cited by 563Sirtuins and Resveratrol in MedicineRedox biology and oxidative stressBiochemical and Molecular Research

The redox state of free nicotinamide-adenine dinucleotide phosphate in the cytoplasm of rat liver

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Veech, R. L., Eggleston, L. V., Krebs, H. A.·1969·Biochemical Journal
DOI 10.1042/bj1150609aPMC PMC1185185
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Abstract

1. The concentrations of the oxidized and reduced substrates of the ‘malic’ enzyme (EC 1.1.1.40) and isocitrate dehydrogenase (EC 1.1.1.42) were measured in freeze-clamped rat livers. By assuming that the reactants of these dehydrogenase systems are at equilibrium in the cytoplasm the [free NADP+]/[free NADPH] ratio was calculated. The justification of the assumption is discussed. 2. The values of this ratio obtained under different nutritional conditions (well-fed, 48hr.-starved, fed with a low-carbohydrate diet, fed with a high-sucrose diet) were all of the same order of magnitude although characteristic changes occurred on varying the diet. The value of the ratio fell on starvation and on feeding with the low-carbohydrate diet and rose slightly on feeding with the high-sucrose diet. 3. The mean values of the ratio were calculated to be between 0·001 and 0·015, which is about 100000 times lower than the values of the cytoplasmic [free NAD+]/[free NADH] ratio. 4. The differences in the redox state of the two nicotinamide–adenine dinucleotide couples can be explained on a simple physicochemical basis. The differences are the result of equilibria that are determined by the equilibrium constants of a number of highly active readily reversible dehydrogenases and transaminases and the concentrations of the substrates and products of these enzymes. 5. The decisive feature is the fact that the NAD and NADP couples share substrates. This sharing provides a link between the redox states of the two couples. 6. The application of the method of calculation to data published by Kraupp, Adler-Kastner, Niessner & Plank (1967), Goldberg, Passonneau & Lowry (1966) and Kauffman, Brown, Passonneau & Lowry (1968) shows that the redox states of the NAD and NADP couples in cardiac-muscle cytoplasm and in mouse-brain cytoplasm are of the same order as those in rat liver. 7. The determination of the equilibrium constant at 38°, pH7·0 and I 0·25 (required for the calculation of the [free NADP+]/[free NADPH] ratio), gave a value of 3·44×10−2m for the ‘malic’ enzyme (with CO2 rather than HCO3− as the reactant) and a value of 1·98×10−2m−1 for glutathione reductase.

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  • NAD+/NADH levels do not change with starvation, whether bound or free fractions are measured.

    “NAD+/NADH levels do not change as a function of starvation, irrespective of whether one measures bound or free fractions of the cofactors”

    From Influence of Metabolism on Epigenetics and Disease (2013) · cites this paper as Veech et al., 1969

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Research works printed but not linked: 12

  1. Bergmeyer, H. U. & Bernt, E. (1963a). In Method8 of Enzymatic Analysis, p. 837. Ed. by Bergmeyer, H. U. New York and London: Academic Press.
  2. Bergmeyer, H. U. & Bernt, E. (1963b). In MethodR of Enzymatic Analy8is, p. 846. Ed. by Bergmeyer, H. U. New York and London: Academic Press.
  3. Brosnan, J. T. (1968). D. Phil. Thesis: University of Oxford.
  4. Bucher, Th. & Ruissmann, W. (1964). Angew. Chem. 75, 881; Angew. Chem. (int. Ed.), 3, 426.
  5. Kauffman, F. C., Brown, J. G., Passonneau, J. V. & Lowry, 0. H. (1968). Fed. Proc. 27, 463.
  6. Klingenberg, M. (1963). In Method8 of Enzymatic Analy8i8, p. 528. Ed. by Bergmeyer, H. U. New York and London: Academic Press.
  7. by Tager, J. M., Papa, S., Quagliariello, E. & Slater, E. C. Amsterdam: Elsevier Publishing Co.
  8. Plaut, G. W. E. (1962). In Methods in Enzymology, vol. 5, p. 645. Ed. by Colowick, S. P. & Kaplan, N. 0. New York and London: Academic Press.
  9. Ed. by Bergmeyer H. U. New York and London: Academic Press.
  10. Veech, R. L. (1968). D. Phil. Thesis: University of Oxford.
  11. Vickery, H. B. & Wilson, D. G. (1960). In Biochemical Preparation8, vol. 7, p. 72. Ed. by Lardy, H. A. New York: John Wiley and Sons Inc.
  12. Williamson, J. R., Kreisberg, R. A. & Felts, P. W. (1966). Proc. nat. Acad. Sci., Wash., 56, 247.

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Authors
Veech, R. L., Eggleston, L. V., & Krebs, H. A.
Affiliations
University of Oxford (GB)
ORCID
Veech, R. L.
Venue
Biochemical Journal
Publisher
Portland Press Ltd.
Published
1969-12-01
Volume
115
Issue
4
Pages
609-619
ISSN
0306-3283 (ISSN-L)
DOI
10.1042/bj1150609a
PMC
PMC1185185
OpenAlex
W1738677317
Cited by
563
References
20
Citations by year
2026: 10 · 2025: 10 · 2024: 14 · 2023: 9 · 2022: 11 · 2021: 18 · 2020: 10 · 2019: 16 · 2018: 10 · 2017: 12 · 2016: 14 · 2015: 11 · 2014: 9 · 2013: 17 · 2012: 11
FWCI
42.54
Type
journal article
Language
en
Open access
Locations
  • Biochemical Journal (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • U.S. Public Health Service
  • Medical Research Council
Topics
  • Health Sciences › Medicine › Geriatrics and Gerontology › Sirtuins and Resveratrol in Medicine
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Redox biology and oxidative stress
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Biochemical and Molecular Research
Keywords
NADPH/NADP+ ratio, NAD+/NADH ratio, malic enzyme, isocitrate dehydrogenase, starvation, low-carbohydrate diet, high-sucrose diet, rat liver, myocardium
MeSH terms
Animals, Cytoplasm, Dietary Carbohydrates, Isocitrate Dehydrogenase, Kinetics, Liver, Malate Dehydrogenase, NAD, NADP, Oxidation-Reduction, Starvation, Sucrose, Rats

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