Skip to main content
Log in

Toluene metabolism in isolated rat hepatocytes: effects of in vivo pretreatment with acetone and phenobarbital

  • Original Investigations
  • Published:
Archives of Toxicology Aims and scope Submit manuscript

Abstract

Hepatocytes isolated from control, acetone- and phenobarbital-pretreated rats were used to study the metabolic conversion of toluene to benzyl alcohol, benzaldehyde, benzoic acid and hippuric acid at low (<100 μM) and high (100–500 μM) toluene concentrations. The baseline formation rates of toluene metabolites (benzyl alcohol, benzoic acid and hippuric acid) were 2.9±01.7 and 10.0±2.3 nmol/mg cell protein/60 min at low and high toluene concentrations, respectively. In vivo pretreatment of rats with acetone and phenobarbital increased the formation of metabolites: at low toluene concentrations 3- and 5-fold, respectively; at high toluene concentrations no significant increase (acetone) and 8-fold increase (phenobarbital). Apparent inhibition by ethanol, 7 and 60 mM, was most prominent at low toluene concentrations: 63% and 69%, respectively, in control cells; 84% and 91% in acetone-pretreated cells, and 32% (not significant) and 51% in phenobarbital-pretreated cells. Ethanol also caused accumulation of benzyl alcohol. The apparent inhibition by isoniazid was similar to that of ethanol at low toluene concentrations. Control and acetone-pretreated cells were apparently resistant towards metyrapone; the decrease was 49% and 64% in phenobarbital-pretreated cells at low and high toluene concentrations, respectively. In these cells, the decrease in presence of combined ethanol and metyrapone was 95% (low toluene concentrations). 4-Methylpyrazole decreased metabolite formation extensively in all groups. Benzaldehyde was only found in the presence of an aldehyde dehydrogenase inhibitor. Increased ratio benzoic/hippuric acid was observed at high toluene concentrations. These results demonstrate that toluene oxidation may be studied by product formation in isolated hepatocytes. However, the influence of various enzymes in the overall metabolism could not be ascertained due to lack of inhibitor specificity.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Similar content being viewed by others

References

  • Amsel LP, Levy G (1970) Effect of ethanol on the conjugation of benzoate and salicylate with glycine in man. Proc Soc Exp Biol Med 135: 813–816

    PubMed  Google Scholar 

  • Carlsson A (1982) Exposure to toluene. Uptake, distribution and elimination in man. Scand J Work Environ Health 8: 43–45

    Google Scholar 

  • Cohr KH, Stokholm J (1979) Toluene. A toxicologic review. Scand J Work Environ Health 5: 71–90

    PubMed  Google Scholar 

  • Crow KE, Cornell NW, Veech RL (1977) The rate of ethanol metabolism in isolated rat hepatocytes. Alcohol Clin Exp Res 1: 43–47

    PubMed  Google Scholar 

  • Elovaara E, Engström K, Nakajima T, Park SS, Gelboin HV, Vainio H (1991) Metabolism of inhaled styrene in acetone-, phenobarbital- and 3-methylcholanthrene-pretreated rats: stimulation and stereochemical effects by induction of cytochromes P450IIE1, P450IIB and P450IA. Xenobiotica 21: 651–661

    PubMed  Google Scholar 

  • Feierman DE, Cederbaum AI (1987) Increased sensitivity of microsomal oxidation of ethanol to inhibition by pyrazole and 4-methylpyrazole after chronic ethanol treatment. Biochem Pharmacol 36: 3277–3283

    Article  PubMed  Google Scholar 

  • Gjerde H, Smith-Kielland A, Normann PT, Mørland J (1990) Driving under the influence of toluene. Forens Sci Int 44: 77–83

    Article  Google Scholar 

  • Ikeda M, Ohtsuji H (1971) Phenobarbital-induced protection against toxicity of toluene and benzene in the rat. Toxicol Appl Pharmacol 20: 30–42

    Article  PubMed  Google Scholar 

  • Lowry OH, Rosebrough NJ, Farr A, Randall RJ (1951) Protein measurement with the Folin phenol reagent. J Biol Chem 193: 265–275

    PubMed  Google Scholar 

  • Marchner H, Tottmar O (1978) A comparative study on the effects of disulfiram, cyanamide and 1-aminocyclopropanol on the acetaldehyde metabolism in rats. Acta Pharmacol Toxicol 43: 219–232

    Article  Google Scholar 

  • Mørland J, Bessessen A (1977) Inhibition of protein synthesis by ethanol in isolated rat parenchymal cells. Biochem Biophys Acta 474: 312–320

    PubMed  Google Scholar 

  • Nakajima T, Wang R-S, Elovaara E, Park SS, Gelboin HV, Hietanen E, Vainio H (1991) Monoclonal antibody-directed characterization of cytochrome P450 isozymes responsible for toluene metabolism in rat liver. Biochem Pharmacol 41: 395–404

    Article  PubMed  Google Scholar 

  • Palakodety RB, Clejan LA, Krikun G, Feierman DE, Cederbaum AI (1988) Characterization and identification of a pyrazole-inducible form of cytochrome P-450. J Biol Chem 263: 878–884

    PubMed  Google Scholar 

  • Persson JO, Terelius Y, Ingelman-Sundberg M (1990) Cytochrome P-450-dependent formation of reactive oxygen radicals: isozyme-specific inhibition of P-450-mediated reduction of oxygen and carbon tetrachloride. Xenobiotica 20: 887–900

    PubMed  Google Scholar 

  • Pyykkö K, Tähti H, Vapaatalo H (1977) Toluene concentrations in various tissues of rats after inhalation and oral administration. Arch Toxicol 38: 169–176

    Article  PubMed  Google Scholar 

  • Sato A, Nakajima T (1985) Enhanced metabolism of volatile hydrocarbons in rat liver followed food deprivation, restriction of carbohydrate intake, and administration of ethanol, phenobarbital, polychlorinated biphenyl and 3-methylcholanthrene: a comparative study. Xenobiotica 15: 67–75

    PubMed  Google Scholar 

  • Sato A, Nakajima T, Koyama Y (1980) Effects of chronic ethanol consumption on hepatic metabolism of aromatic and chlorinated hydrocarbons in rats. Br J Ind Med 37: 382–386

    PubMed  Google Scholar 

  • Sato A, Nakajima T, Koyama Y (1981) Dose-related effects of a single dose of ethanol on the metabolism in rat liver of some aromatic and chlorinated hydrocarbons. Toxicol Appl Pharmacol 60: 8–15

    Article  PubMed  Google Scholar 

  • Seglen PO (1973) Preparation of rat liver cells. III. enzymatic requirements for tissue dispersion. Exp Cell Res 82: 391–398

    Article  PubMed  Google Scholar 

  • Takahashi S, Kagawa M, Inagaki O, Akane A, Fukui Y (1987) Metabolic interaction between toluene and ethanol in rabbits. Arch Toxicol 59: 307–310

    Article  PubMed  Google Scholar 

  • Ullrich V, Weber P, Wollenberg P (1975) Tetrahydrofurane — an inhibitor for ethanol-induced liver microsomal cytochrome P-450. Biochem Biophys Res Commun 64: 808–813

    Article  PubMed  Google Scholar 

  • Waldron HA, Cherry N, Johnstone JD (1983) The effects of ethanol on blood toluene. Int Arch Occup Environ Health 51: 365–369

    Article  PubMed  Google Scholar 

  • Wallén M, Näslund PH, Byfält Nordquist M (1984) The effects of ethanol on the kinetics of toluene in man. Toxicol Appl Pharmacol 76: 414–419

    Article  PubMed  Google Scholar 

  • Wallén M, Johanson G, Nordquist MB (1985) The effects of ethanol on kinetics of toluene in perfused rat liver. Toxicol Lett 26: 59–60

    Article  PubMed  Google Scholar 

  • Wang R-S, Nakajima T (1991) Kinetic studies on toluene metabolism in ethanol- and phenobarbital-induced rat liver microsomes in vitro. Arch Toxicol 65: 39–44

    PubMed  Google Scholar 

  • Åstrand I, Erhner-Samuel H, Kilbom Å, Övrum P (1972) Toluene exposure I. Concentration in alveolar air and blood at rest and during exercise. Work Environ Health 9: 119–130

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Rights and permissions

Reprints and permissions

About this article

Cite this article

Smith-Kielland, A., Ripel, Å. Toluene metabolism in isolated rat hepatocytes: effects of in vivo pretreatment with acetone and phenobarbital. Arch Toxicol 67, 107–112 (1993). https://doi.org/10.1007/BF01973680

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI: https://doi.org/10.1007/BF01973680

Key words

Navigation