Elsevier

Toxicology

Volume 128, Issue 1, 26 June 1998, Pages 53-61
Toxicology

Temporal variation in hepatotoxicity and metabolism of acetaminophen in mice

https://doi.org/10.1016/S0300-483X(98)00046-8Get rights and content

Abstract

Temporal variation in metabolism and hepatotoxicity of acetaminophen (APAP) was examined using male ICR mice. Animals were injected with a single dose of APAP (400 mg/kg, i.p.) at 08:00, 14:00 or 20:00 h. APAP at this dose was markedly hepatotoxic to mice when administered at 20:00 h as determined by increases in serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, and by decreases in hepatic glucose-6-phosphatase (G-6-Pase) activity. However, mice appeared to be entirely insensitive to an identical dose of APAP given either at 08:00 or 14:00 h. Hepatic glutathione (GSH) level was significantly higher at 08:00, but no difference in GSH levels between 14:00 and 20:00 h was observed in normal mice. APAP and its metabolites in blood were monitored using HPLC for 3 h following the treatment. There were no significant differences in the plasma concentrations of APAP, APAP-glucuronide, APAP-sulfate, or APAP-mercapturate among the mice treated with this drug at 08:00, 14:00 or 20:00 h. However, the APAP-cysteine and APAP-GSH levels measured at 1 h following the APAP treatment were significantly lower in mice treated with this analgesic either at 14:00 or 20:00 h. In vitro hepatic microsomal p-nitrophenol hydroxylase activities were not different between 08:00, 14:00 and 20:00 h. But ethoxyresorufin O-deethylase and aminopyrine N-demethylase activities measured at 14:00 h were significantly lower than those of 08:00 or 20:00 h. Thus, the greater hepatotoxicity of APAP administered at 20:00 h appears to be related to the marked decrease in hepatic GSH at this time period, whereas the simultaneous reduction in APAP activation may be responsible for the lack of hepatotoxicity in mice treated with this analgesic at 14:00 h. These results suggest that the temporal variation in hepatotoxicity and metabolism of APAP is determined by interactions of multiple factors including the hepatic GSH level and drug metabolizing activities.

Introduction

It has been well accepted that biological response to drugs and chemicals may not be constant throughout a day (Halberg, 1969, Moore Ede, 1973, Reinberg, 1979). Conceptually such variations may be dependent on changes in the sensitivity of target organs to a particular agent, on alterations in drug disposition including metabolism and excretion, and/or on rhythmic fluctuations in the availability of endogenous substances such as glutathione (GSH), of which hepatic concentrations have been shown to exhibit a circadian rhythmicity (Jaeger et al., 1973, Schnell et al., 1984).

Acetaminophen (APAP), a widely used analgesic–antipyretic, is safe at therapeutic doses, but upon a large overdose severe hepatotoxicity may result in experimental animals and humans. At low dose levels APAP is detoxified mainly through sulfation and glucuronidation in animals (Jollow et al., 1974). Following an overdose, however, APAP is increasingly metabolized into a reactive metabolite, N-acetyl-p-benzoquinonimine (NAPQI), by cytochrome P450-mediated reactions, which is normally detoxified by conjugation with hepatic GSH. When the generation of reactive metabolites exceeds the availability of hepatic GSH for conjugation, covalent binding of the reactive metabolite to macromolecules may result, an event that correlates with hepatic necrosis. Considering the rhythmicity of hepatic GSH level and its critical role in detoxification of APAP, it is suspected that there would be time-dependent variations in APAP-induced effects. In fact a circadian rhythm in APAP-induced lethality was described in mice (Schnell et al., 1983, Schnell et al., 1984).

The present study was designed to further investigate the temporal variation in response of animals to APAP. We have examined various factors associated with metabolic activation or detoxification of APAP to determine the mechanism responsible for the time-dependent fluctuations in hepatotoxicity and metabolism of this drug.

Section snippets

Animals and treatments

Adult ICR male mice (Animal Breeding Center, Seoul National University) weighing 30–35 g were used throughout the study. Animals were housed in temperature (22±2°C) and humidity (55±5%) controlled rooms with a 12-h light:dark cycle (light, 08:00–20:00 h). Regular lab chow and tap water were allowed ad libitum until drug administration. Animals were injected with APAP (400 mg/kg, i.p.) either at 08:00, 14:00 or 20:00 h. APAP was injected as a saturated solution in saline (20 ml/kg), prepared by

Variations in APAP-induced hepatotoxicity

Mice were injected with a single dose of APAP (400 mg/kg, i.p.) at 08:00, 14:00 or 20:00 h, and the resulting hepatotoxicity was measured 24 h following each treatment (Table 1). APAP, at the dose used, was not hepatotoxic when administered either at 08:00 or 14:00 h, as measured by changes in serum AST and ALT activities. However, an identical dose of this analgesic given at 20:00 h resulted in a remarkable elevation in these parameters, more than 10- and 50-fold increases in AST and ALT,

Discussion

In the present study an intraperitoneal dose of APAP (400 mg/kg) was administered to mice at 08:00, 14:00 or 20:00 h. Treatment of animals with APAP at 08:00 or 14:00 h did not affect the serum AST/ALT activities, but an identical dose of APAP given at 20:00 h elevated the parameters for hepatotoxicity measured in this study significantly. Similarly, hepatic G-6-Pase activity was depressed by the APAP administration made at 20:00 h only. Among the time points examined, a significantly higher

Acknowledgements

This work was supported by the Korea Science and Engineering Foundation (KOSEF) through the Research Center for New Drug Development (RCNDD) at Seoul National University.

References (30)

  • G.J. Traiger et al.

    Differences in the potentiation of carbon tetrachloride in rats by ethanol and isopropanol pretreatment

    Toxicol. Appl. Pharmacol.

    (1971)
  • F. Halberg

    Chronobiology

    Ann. Rev. Physiol.

    (1969)
  • D. Howie et al.

    Paracetamol metabolism following overdosage: application of high performance liquid chromatography

    J. Pharm. Pharmacol.

    (1977)
  • R.J. Jaeger et al.

    Diurnal variation of hepatic glutathione concentration and its correlation with 1,1-dichloroethylene inhalation toxicity in rats

    Res. Commun. Chem. Pathol. Pharmacol.

    (1973)
  • D.J. Jollow et al.

    Acetaminophen-induced hepatic necrosis

    Pharmacology

    (1974)
  • Cited by (44)

    • Gut microbiota mediates diurnal variation of acetaminophen induced acute liver injury in mice

      2018, Journal of Hepatology
      Citation Excerpt :

      Female mice are usually resistant to APAP-induced hepatotoxicity.8 Therefore, male mice were mostly used to report the diurnal variation of APAP-induced acute liver injury.14,15 However, we found the female mice that received male ZT12 feces exhibited increased necrosis compared with female mice that received male ZT0 feces (Fig. S14), indicating that gut microbiota may also influence the diurnal variation of liver damage induced by APAP in female mice, though the microbiome alone makes a very modest contribution to the resistance of female mice to APAP.

    • Microbiota Diurnal Rhythmicity Programs Host Transcriptome Oscillations

      2016, Cell
      Citation Excerpt :

      We therefore administered APAP at different circadian times (ZT0 versus ZT12) and assessed APAP-induced hepatotoxicity by the measurement of liver enzyme release as well as liver histology. In line with previous reports (Johnson et al., 2014; Kim and Lee, 1998), mice featured dramatically exacerbated liver toxicity when APAP was injected at ZT12 as compared to ZT0 (Figures 7H–7K). This diurnal variation was clock-dependent, as Per1/2−/− mice did not feature differential hepatotoxicity between ZT0 and ZT12 (Figures S7D–S7G).

    View all citing articles on Scopus
    View full text