C Ribiere

Université René Descartes - Paris 5, Lutetia Parisorum, Île-de-France, France

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Publications (27)75.33 Total impact

  • Dominique Santiard · Catherine Ribière · Roger Nordmann · C Houee-Levin
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    ABSTRACT: The reactions of free radicals derived from ethanol metabolism with Cu,Zn SOD were studied. 1-Hydroxyethyl radicals were generated by gamma radiolysis of a N2O-saturated ethanolic solution (10(-2) M) in phosphate buffer (10(-3) M, pH 7.4). To generate acetyl radicals by gamma radiolysis, we used ethylene glycol (10(-2) M) in phosphate buffer (10(-3) M, pH 7.4). This allows us to avoid the use of acetaldehyde, which may be toxic toward various cellular constituents. We have previously reported that HO. radicals reacting with either acetaldehyde or ethylene glycol produce the same free radicals (Santiard et al., 1991, J. Chim. Phys. 88, 967-976). the rate constant reaction of 1-hydroxyethyl free radicals with Cu,Zn-SOD was measured separately by competition kinetics with the spin trapping agent alpha-(4-pyridyl 1-oxide) N-terbutylnitrone (4-POBN), after having measured the rate constant of scavenging of 1-hydroxyethyl free radicals by 4-POBN in the absence of SOD. We found k1 (4-POBN + 1-hydroxyethyl radical) = 4.2 10(5) M-1 s-1 and kR (SOD + 1-hydroxyethyl radical) = 6.8 10(5) M-1 s-1). 1-Hydroxyethyl or acetyl radicals produced dose-dependent Cu,Zn-SOD inactivation. The inactivation rate constant of Cu,Zn-SOD by 1-hydroxyethyl radicals is ki = 1.13 10(4) M-1 s-1. Free radicals derived from ethanol metabolism can thus react SOD leading to enzyme inactivation, besides the fact that the reactivities of 1-hydroxyethyl radicals with 4-POBN and with proteins such as Cu,Zn SOD are of the same order of magnitude could explain the difficulties to trap in vivo these radicals.
    No preview · Article · Aug 1995 · Free Radical Biology and Medicine
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    ABSTRACT: Functional characteristics of mitochondria isolated from liver, brain and heart were studied in ethanol-fed rats using ethanol administration in drinking water as a model of moderate alcohol intoxication. Our results show a slight decrease in liver cytochrome aa3 content, the mitochondrial alteration which is most consistently observed during chronic ethanol feeding. In liver and heart mitochondria, ethanol consumption led to an increase in state 3 respiration with NAD(+)-linked substrates, whereas no changes were apparent in respiration rates with succinate as substrate. However a decrease was found in state 3 respiration with succinate in brain mitochondria isolated from ethanol-fed rats. Submitochondrial particles (SMP) were used to study the superoxide radical (O2-.) production at the level of antimycin-inhibited regions of the respiratory chain. It appears that there is no clear correlation between ethanol effects on respiration and O2-. production. Whereas O2-. generation remained unchanged in heart mitochondria, an elevation of O2-. generation was observed in brain mitochondria, and in contrast, the rate of O2-. production was decreased in liver mitochondria of the ethanol-group in comparison to the control-group. Our findings support a tissue specificity for the toxic effects of ethanol towards the mitochondria and indicate that mitochondrial free radical mechanisms are involved in ethanol-induced toxicity in the brain.
    No preview · Article · Jun 1994 · Biochemical Pharmacology
  • Catherine Ribière · Isabelle Hininger · Hélène Rouach · Roger Nordmann
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    ABSTRACT: Cellular protection against free radical reactions was measured in myocardium from ethanol-fed rats using ethanol administration in drinking water as a model of moderate alcohol intoxication. The activities of Cu,Zn-superoxide dismutase (SOD) and glutathione-S-transferase were higher in ethanol-fed rats than in controls, whereas Mn-SOD, catalase and glutathione peroxidase activities were not altered by ethanol treatment. Myocardial zinc was higher and selenium concentration lower in ethanol-fed rats than in controls. Ethanol consumption, which failed to modify the myocardial vitamin E level, did not result in increased lipid peroxidation, but decreased cytosolic and membraneous protein thiols.
    No preview · Article · Nov 1992 · Biochemical Pharmacology
  • Roger Nordmann · Catherine Ribière · Hélène Rouach
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    ABSTRACT: Numerous experimental data reviewed in the present article indicate that free radical mechanisms contribute to ethanol-induced liver injury. Increased generation of oxygen- and ethanol-derived free radicals has been observed at the microsomal level, especially through the intervention of the ethanol-inducible cytochrome P450 isoform (CYP2E1). Furthermore, an ethanol-linked enhancement in free radical generation can occur through the cytosolic xanthine and/or aldehyde oxidases, as well as through the mitochondrial respiratory chain. Ethanol administration also elicits hepatic disturbances in the availability of non-safely-sequestered iron derivatives and in the antioxidant defense. The resulting oxidative stress leads, in some experimental conditions, to enhanced lipid peroxidation and can also affect other imporant cellular components, such as proteins or DNA. The reported production of a chemoattractant for human neutrophils may be of special importance in the pathogenesis of alcoholic hepatitis. Free radical mechanisms also appear to be implicated in the toxicity of ethanol on various extrahepatic tissues. Most of the experimental data available concern the gastric mucosa, the central nervous system, the heart, and the testes. Clinical studies have not yet demonstrated the role of free radical mechanisms in the pathogenesis of ethanol-induced cellular injury in alcoholics. However, many data support the involvement of such mechanisms and suggest that dietary and/or pharmacological agents able to prevent an ethanol-induced oxidative stress may reduce the incidence of ethanol toxicity in humans.
    No preview · Article · Jan 1992 · Free Radical Biology and Medicine
  • I Hininger · C Ribiere · R Nordmann
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    ABSTRACT: A significant decrease in myocardial creatine kinase (CK) activity is apparent 2 hr after an acute ethanol load (2.3 g/kg, i.p.) in the rat. A lower dose (1.15 g/kg, i.p.), as well as ethanol addition in vitro up to 50 mM, do not affect this activity. Pretreatment with allopurinol (146 mumols/kg, i.p.) given at 16 hr and at 30 min before ethanol (2.3 g/kg) or with desferrioxamine (152 mumols/kg, i.p.) 30 min before ethanol failed to prevent the ethanol-induced decrease in CK activity. By contrast, propranolol (17 mumols/kg, i.p.), administered 30 min before ethanol elicited an enhanced CK activity in both control and ethanol-treated rats. This finding is likely related to the beta-blocking action and/or antioxidant properties of propranolol. Chronic ethanol intake (18% in calories) for 4 weeks also induced a decrease in myocardial CK activity, which could play a role in the pathogenesis of alcoholic cardiomyopathy.
    No preview · Article · Feb 1991 · Alcohol and Alcoholism
  • R Nordmann · C Ribière · H Rouach
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    ABSTRACT: An ethanol-induced oxidative stress is not restricted to the liver, where ethanol is actively oxidized, but can affect various extrahepatic tissues as shown by experimental data obtained in the rat during acute or chronic ethanol intoxication. Most of these data concern the central nervous system, the heart and the testes. An acute ethanol load has been reported to enhance lipid peroxidation in the cerebellum. This is accompanied by an increase in the cytosolic concentration of low-molecular-weight iron derivatives which may contribute to the generation of aggressive free radicals. The ethanol-induced decrease in the main antioxidant systems (superoxide dismutase, alpha-tocopherol, ascorbate and selenium) is a likely contributor to the cerebellar oxidative stress. Most of these disturbances can be prevented by allopurinol administration. Some experimental data support also the occurrence of pro- and anti-oxidant disturbances in the cerebellum and in other regions of the central nervous system after chronic ethanol administration. Chronic ethanol administration enhances lipid peroxidation in the heart. The increased conversion of xanthine dehydrogenase into xanthine oxidase as well as the activation of peroxisomal acyl CoA-oxidase linked to ethanol administration could contribute to the oxidative stress. Chronic ethanol administration elicits in the testes an enhancement in mitochondrial lipid peroxidation and a decrease in the glutathione level, which appear to be correlated to the gross testicular atrophy observed. Vitamin A supplementation attenuates the changes in lipid peroxidation, glutathione and testicular morphology. Whether the reported disturbances are involved in the pathogenesis of the tissue disorders observed in alcoholic patients remains unanswered.(ABSTRACT TRUNCATED AT 250 WORDS)
    No preview · Article · Feb 1990 · Alcohol and Alcoholism
  • H. Rouach · C. Ribiere · M.K. Park · C. Saffar · R. Nordmann
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    ABSTRACT: An acute ethanol load (50 mmol/kg, i.p.) results in an increase in lipid peroxidation and a decrease in the levels of vitamins C and E in rat cerebellum. The decrease in vitamin E is prevented by allopurinol administration. These results suggest that acute ethanol load induces an oxidative stress at the cerebellar level. Brain mitochondrial superoxide production is, however, unchanged. Moreover, the brain mitochondria of such ethanol-treated rats are characterized by a marked inhibition of state 3 respiratory activity.
    No preview · Article · Dec 1987 · Bioelectrochemistry and Bioenergetics
  • R Nordmann · C Ribière · H Rouach
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    ABSTRACT: Lipoperoxidation, a degradative process of membranous polyunsaturated fatty acids, has been suggested to represent an important mechanism in the pathogenesis of ethanol toxicity on the liver and possibly also on the brain. Catalysis by transition metals, especially iron, is involved in the biosynthesis of free radicals contributing to lipid peroxidation. Although the exact nature of the redox-active iron implicated in this catalysis is still unknown, it has been well established that lipid peroxidation can be prevented in vitro by iron chelators such as desferrioxamine. Deprivation of redox-active iron through desferrioxamine inhibits by about 50% the microsomal oxidation of ethanol in vitro and reduces very significantly in vivo the overall ethanol elimination rate in rats. Administration of desferrioxamine together with ethanol also reduces the ethanol-induced disturbances in the antioxidant defense mechanisms of the hepatocyte. It also reduces in mice both the severity of physical dependence on ethanol and lethality following the acute administration of a narcotic dose of ethanol. Chronic overloading of rats with iron results, on the opposite, in an increased rate of ethanol elimination, although alcohol dehydrogenase and catalase activities are reduced and cytochrome P-450 depleted in the liver of such iron-overloaded animals. The magnitude of the ethanol-induced increase in lipid peroxidation and decrease in the major membranous antioxidant, alpha-tocopherol, is exacerbated in iron-overloaded rats. Several disturbances of iron metabolism have been reported in human alcoholics. Their contribution to ethanol toxicity appears very likely in the case of hepatic siderosis associated with alcohol abuse. Ethanol could however disturb iron metabolism even in the absence of gross abnormalities of the total iron stores. It is suggested that ethanol intoxication could increase cellular redox-active iron, thus contributing to an enhanced steady-state concentration of reactive-free radicals. This oxidative stress would lead to lipoperoxidative damage and cellular injury.
    No preview · Article · Feb 1987 · Enzyme
  • C Ribiere · D Sabourault · C Saffar · R Nordmann
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    ABSTRACT: Two hours after an acute ethanol load (50 mmol/kg, i.p.), brain mitochondrial superoxide production was unchanged. This is contrary to our previous findings concerning liver mitochondria. On the other hand, the ethanol treatment caused a marked inhibition of respiration stimulated by phosphate plus ADP (with succinate or pyruvate plus malate as substrates) (state 3) in the brain mitochondria, whereas it did not exert any modification on the hepatic mitochondrial electron transport chain.
    No preview · Article · Feb 1987 · Alcohol and alcoholism (Oxford, Oxfordshire). Supplement
  • R Nordmann · C Ribiere · H Rouach

    No preview · Article · Feb 1987 · Progress in clinical and biological research
  • R Nordmann · C Ribière · H Rouach · J Sinaceur · D Sabourault

    No preview · Article · Dec 1985 · Bulletin de l'Académie nationale de médecine
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    ABSTRACT: Cytosolic superoxide dismutase (SOD) activity was found to increase with time during HeLa cell culture, this increase being due exclusively to Mn-SOD. Infection of the cells by Chlamydia trachomatis resulted in a further enhancement of this Mn-SOD activity, whereas cytosolic catalase activity was decreased in these infected cells. Superoxide (O-2.) being able to induce Mn-SOD and to inhibit catalase, these data suggest that Chlamydia trachomatis infection could be responsible for an increase in O-2. production by the infected HeLa cells.
    No preview · Article · Apr 1985 · Pathologie Biologie
  • C Ribiere · J Sinaceur · D Sabourault · R Nordmann
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    ABSTRACT: The administration of an acute ethanol load (2.3 g/kg, IP) to rats is followed by a decrease of the hepatic activity of cytosolic catalase, a decrease which precedes a reduction in the cytosolic Cu, Zn-superoxide dismutase (SOD) activity. Desferrioxamine, an iron chelator and scavenger of superoxide radicals, administered prior to ethanol, prevents the changes in the cytosolic catalase activity, changes which are unaffected by the administration of allopurinol, an inhibitor of xanthine oxidase. These data favour the hypothesis that acute ethanol results in an overproduction of oxygen free radicals which affects primarily the cytosolic catalase activity and increases hereby susceptibility of Cu, Zn-SOD to these radicals. They suggest also that xanthine oxidase does not play a major role in oxygen radical production in the liver cytosol during acute alcohol intoxication.
    No preview · Article · Feb 1985 · Alcohol
  • C Ribière · J Sinaceur · J Nordmann · R Nordmann
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    ABSTRACT: After acute ethanol administration (2.3 g/kg) peroxisomal and extra-peroxisomal catalase activities were affected in opposite directions. As long as ethanol was present, peroxisomal catalase activity was enhanced, but unaffected by amino-triazole (AT) injection. Extra-peroxisomal catalase activity was decreased during the 24hr following ethanol administration and was also inhibited after AT injection. Whereas mitochondrial manganese-dependent superoxide dismutase (Mn-SOD) was unaffected, the cytosolic Cu,Zn-SOD activity was decreased. The time-course of this decrease suggests that acute ethanol administration affects primarily extra-peroxisomal catalase activity, thus rendering cytosolic superoxide dismutase more exposed to oxygen derivatives.
    No preview · Article · Feb 1985 · Alcohol and Alcoholism
  • Jamal Sinaceur · Catherine Ribière · Joseph Nordmann · Roger Nordmann

    No preview · Article · Jun 1984 · Biochemical Pharmacology

  • No preview · Article · Sep 1983 · Biochemical Pharmacology
  • C Ribière · J Sinaceur · J Nordmann · R Nordmann
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    ABSTRACT: Manganese superoxide dismutase (Mn-SOD) studied during ethanol vapor inhalation shows no changes during the inhalation period (4 days) and a transient increase 12 hours after ethanol withdrawal. A significant decrease in cytosolic Cu-Zn-SOD is found at the end of the inhalation period and was sustained during 48 hours following ethanol withdrawal. It is suggested that this decrease in Cu-Zn-SOD activity might be related to an inactivation of the enzyme linked to the increase in hydroxyl radical production related to ethanol metabolism. Cytosolic catalase is reduced at the end of the ethanol inhalation period. This decrease could be related to an enhanced superoxide radical concentration linked to the reduced Cu-Zn-SOD activity.
    No preview · Article · Feb 1983 · Pharmacology Biochemistry and Behavior
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    Catherine Ribiere · Hélène Rouach · Joseph Nordmann · Roger Nordmann
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    ABSTRACT: The two hepatic enzymes tyrosine aminotransferase (TAT) (EC and tryptophan oxygenase (TO) (EC. are known to be induced by treatment of rats with corticosteroids or by stress conditions in which the circulating concentration of these hormones is increased. Our studies concerning the effects of ethanol on TAT activity have shown that ethanol increases basal TAT activity only in starved rats, while it inhibits the early phase of TAT cortisol induction in starved as well as in fed rats. It seems therefore of interest to test whether ethanol administration in the same conditions as those used for studying TAT affects also cortisol induction of TO in starved and in fed rats. These results show that acute ethanol administration results in an increase in basal TO activity in starved rats and an inhibition of the early phase of TO induction in starved as well as in fed animals. In the experimental conditions used, the acute ethanol effects on TO and TAT appear thus similar.
    Full-text · Article · Sep 1980 · FEBS Letters
  • Roger Nordmann · Hélène Rouach · Catherine Ribière · Joseph Nordmann

    No preview · Article · Jul 1980 · Drug and Alcohol Dependence
  • H Rouach · C Ribiere · J Nordmann · R Nordmann
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    ABSTRACT: In starved rats, ethanol administered acutely enhances tryptophan oxygenase (TO) and tyrosine aminotransferase (TAT) activities. Ethanol also inhibits the early phase of the cortisol-mediated TO and TAT induction. Ethanol administered at the same time as tryptophan does not modify the tryptophan-mediated TO and TAT induction. In cortisol-pretreated rats, ethanol enhances the subsequent TO and TAT induction whereas no additive effects are observed when ethanol is injected together with tryptophan. These results suggest that ethanol mimics the effects of tryptophan on TO and TAT activities. In fed animals, ethanol alone does not result in increased TO and TAT activities, but inhibits their cortisol induction. It increases TO activities when given together with a tryptophan dose which, when given alone, does not enhance these activities. It is suggested that the observed inhibitory effects of ethanol on cortisol-mediated TO and TAT induction in starved and fed animals are related to a defective cortisol transport in the liver cells.
    No preview · Article · Feb 1980 · Pharmacology Biochemistry and Behavior