In vitro/in vivo effects of 7,8-benzoflavone on aryl hydrocarbon hydroxylase activity of mice.

C. Kiyohara, T. Hirohata

Research output: Contribution to journalArticle

Abstract

The activity of aryl hydrocarbon hydroxylase (AHH) in mouse liver microsomes was assayed in vitro in the presence of 7,8-benzoflavone (7,8-BF). The mice had been previously treated with the AHH inducer 3-methylcholanthrene (MC), 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or vehicle (olive oil) alone. The effects of 7,8-BF on the AHH activity were markedly different according to the genetic responsiveness of the mice towards aromatic hydrocarbons (Ah). 7,8-BF had either an inhibitory or an enhancing effect on AHH, depending on the Ah responsiveness and previous treatment with MC or TCDD. In contrast, a single administration of 7,8-BF induced microsomal AHH, but the effect was much lower than MC or TCDD in both strains of mice. Simultaneous treatment or pre-treatment with 7,8-BF produced an inhibitory effect on AHH induction by MC or TCDD. Post-treatment with 7,8-BF inclined to promote the induction of AHH by MC or TCDD. These results suggest that the inhibitory effect of 7,8-BF is more exaggerated in vitro than in vivo. Inhibitory effects would be limited to AHH induction from MC or TCDD in in vitro studies, while they would depend on the time of application or Ah responsiveness in studies in vitro.

Original languageEnglish
Pages (from-to)413-416
Number of pages4
JournalVeterinary and human toxicology
Volume34
Issue number5
Publication statusPublished - Oct 1992

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Aryl Hydrocarbon Hydroxylases
unspecific monooxygenase
tetrachlorodibenzo-p-dioxin
Methylcholanthrene
mice
Aromatic Hydrocarbons
aromatic hydrocarbons
in vitro studies
liver microsomes
alpha-naphthoflavone
In Vitro Techniques
Liver Microsomes
olive oil
Liver
Polychlorinated Dibenzodioxins
1,4-dioxin
pretreatment

All Science Journal Classification (ASJC) codes

  • Toxicology
  • veterinary(all)
  • Health, Toxicology and Mutagenesis

Cite this

In vitro/in vivo effects of 7,8-benzoflavone on aryl hydrocarbon hydroxylase activity of mice. / Kiyohara, C.; Hirohata, T.

In: Veterinary and human toxicology, Vol. 34, No. 5, 10.1992, p. 413-416.

Research output: Contribution to journalArticle

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