Isotopic probes into pathways of ethanol metabolism

Rognstad, Robert

doi:10.1016/0003-9861(74)90513-x

Cited by 32 publications

(2 citation statements)

References 26 publications

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“…Provided that it obeys the same inhibition kinetics with 4-methyl pyrazole, and that intracellular 4-methyl pyrazole concentration does not differ from the extracellular concentration, it may be calculated that its activity may amount to about 10% of the rate of the alcohol dehydrogenase reaction in the cell. This value compares well with estimates obtained with different techniques [64], but is lower than postulated by some authors [10,65]. Others have estimated low activities of the nonalcohol-dehydrogenase systems [66 -681 or attributed the activity to catalase [4].…”

Section: Hepatocytessupporting

confidence: 87%

The ^D(V/K) Isotope Effect of the Cytochrome P‐450‐Mediated Oxidation of Ethanol and Its Biological Applications

Damgaard

1982

European Journal of Biochemistry

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Purified preparations of rat liver microsomes consist of flat discoid structures, presumably vesicles. They catalyze oxidation of ethanol to acetaldehyde in the absence of alcohol dehydrogenase and catalase with a specific activity of 1.4-53 nmol acetaldehyde formed min-' (nmol cytochrome P-450)-'. The "( V / K ) isotope effect of this microsomal ethanol-oxidizing system was 1.15. This value is clearly different from those of alcohol dehydrogenase (3.0) and catalase (1.9). Particulate aldehyde dehydrogenases present in the preparation are active at unphysiologically high concentrations of aldehyde. Coincidently, the activity of the microsomal ethanoloxidizing system, was well as the " ( V / K ) isotope effect associated with it, was increased significantly. This observation confirms the enzymic nature of the reaction studied.In microsomes washed once in KCI, ethanol oxidation was catalyzed mainly by catalase, but also by the microsomal ethanol-oxidizing system, as judged from the "( V / K ) isotope effect upon the net reaction. In the presence of sodium azide alcohol dehydrogenase activity could be demonstrated. In hepatocytes from rat or pig, 4-methyl pyrazole at high concentrations reduced the rate of ethanol oxidation to 3-10%. The " ( V / K ) isotope effect upon the residual ethanol oxidation reflected activities of both catalase and the microsomal ethanoloxidizing system. The activity of this latter system was inhibited by 4-methyl pyrazole competitively with ethanol, Ki = 5.7 mM. When this inhibition is taken into account, the uninhibited membrane system activity in these cells amount to maximally 10% of the rate of ethanol oxidation in the absence of inhibitor.

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Section: Hepatocytessupporting

confidence: 87%

The ^D(V/K) Isotope Effect of the Cytochrome P‐450‐Mediated Oxidation of Ethanol and Its Biological Applications

Damgaard

1982

European Journal of Biochemistry

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“…Such a change is known to decrease the affinity to the hydrogen donor, formic acid or ethanol (Keilin & Hartree, 1955;Oshino et al, 1973). A similar change in the apparent isotope effect upon peroxidation of ethanol has been predicted on a theoretical basis by Rognstad (1974). The fact that the V/K 2H isotope effect of 1.5 for peroxidation of formate could only be reproduced in vivo when dilution of the labelled compound with endogenous formate could occur (Aebi et al, 1957) supports this view, as such dilution prevents the appearance of V isotope effects (Simon & Palm, 1966).…”

Section: Resultsmentioning

confidence: 78%

Isotope effect in peroxidation of deuterium-labelled ethanol by liver catalase

Damgaard¹

1980

Biochemical Journal

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The kinetic V/K isotope effect upon peroxidation of (1R)-[1-2H1]ethanol by liver catalase was studied by using a radiochemical assay with both 3H ad 14C as tracers. The value of 1.9 found is in agreement with the value of 2.52 for peroxidation of (1R)-[1-3H1]ethanol according to the 'Swain equation' [Swain, Stivers, Ruver & Schaad (1958) J. Am. Chem. Soc. 80, 5885-5893]. There was no isotope effect on V, the catalase haem up to 500 min-1. Even at rates 20-fold higher the isotope effect on V may not be different from 1. A detailed description of the synthesis of the 2H- and 3H-substituted ethanol compounds and the analysis of these has been deposited as Supplementary Publication SUP 50110 (5 pages) at the British Library Lending Division, Boston Spa, Wetherby, W. Yorkshire LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1978) 169,5.

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Acetaldehyde—Its Metabolism and Role in the Actions of Alcohol

Lindros¹

1978

Research Advances in Alcohol and Drug Problems

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Isotopic probes into pathways of ethanol metabolism

Cited by 32 publications

References 26 publications

The ^D(V/K) Isotope Effect of the Cytochrome P‐450‐Mediated Oxidation of Ethanol and Its Biological Applications

The ^D(V/K) Isotope Effect of the Cytochrome P‐450‐Mediated Oxidation of Ethanol and Its Biological Applications

Isotope effect in peroxidation of deuterium-labelled ethanol by liver catalase

Acetaldehyde—Its Metabolism and Role in the Actions of Alcohol

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Isotopic probes into pathways of ethanol metabolism

Cited by 32 publications

References 26 publications

The D(V/K) Isotope Effect of the Cytochrome P‐450‐Mediated Oxidation of Ethanol and Its Biological Applications

The D(V/K) Isotope Effect of the Cytochrome P‐450‐Mediated Oxidation of Ethanol and Its Biological Applications

Isotope effect in peroxidation of deuterium-labelled ethanol by liver catalase

Acetaldehyde—Its Metabolism and Role in the Actions of Alcohol

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Product

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The ^D(V/K) Isotope Effect of the Cytochrome P‐450‐Mediated Oxidation of Ethanol and Its Biological Applications

The ^D(V/K) Isotope Effect of the Cytochrome P‐450‐Mediated Oxidation of Ethanol and Its Biological Applications