Differential effects of antioxidants, steroids and other compounds on benzo(a)pyrene 3-hydroxylase activity in various tissues of rat
Open Access
- 1 July 1979
- journal article
- research article
- Published by Springer Nature in British Journal of Cancer
- Vol. 40 (1) , 105-112
- https://doi.org/10.1038/bjc.1979.146
Abstract
Antioxidants were found to inhibit the mixed-function oxidation of benzo(a)pyrene in several tissues of untreated and 3-methylcholanthrene-pretreated rats. The enzyme systems in the liver, kidney and stomach were much more susceptible to inhibition than those in the lung, adrenal, colon and small intestine. In all tissues except the stomach it was found that 3-methylcholanthrene pretreatment led to a decrease in inhibition of benzo(a)pyrene 3-hydroxylase activity. It is suggested that antioxidants exert their protective effect against cancer by inhibiting the formation of carcinogenic metabolites. Of the various steroids tested, only 17 beta-oestradiol and oestrone were significantly inhibitory in most tissues. Cholesterol was found to increase benzo(a)pyrene 3-hydroxylase activity in the gastrointestinal tract.Keywords
This publication has 36 references indexed in Scilit:
- The mitigating effect of dietary antioxidants on chemically-induced carcinogenesisCellular and Molecular Life Sciences, 1978
- Evidence for a 2,3-epoxide as an intermediate in the microsomal metabolism of benzo[a]pyrene to 3-hydroxybenzo[a] pyreneBiochemical and Biophysical Research Communications, 1977
- The isolation of rat intestinal microsomes with stable cytochrome P-450 and their metabolism of benzo(α)pyreneArchives of Biochemistry and Biophysics, 1976
- The binding of benzo[α] pyrene to DNA does not involve substitution at the 6-positionChemico-Biological Interactions, 1976
- Metabolic activation of aromatic hydrocarbons in purified rat liver nuclei: induction of enzyme activities and binding to DNA with and without monooxygenase-catalyzed formation of active oxygen.Proceedings of the National Academy of Sciences, 1976
- Environmental factors and cancer incidence and mortality in different countries, with special reference to dietary practicesInternational Journal of Cancer, 1975
- Effects of Inducers and Epoxide Hydrase on the Metabolism of Benzo[ a ]pyrene by Liver Microsomes and a Reconstituted System: Analysis by High Pressure Liquid ChromatographyProceedings of the National Academy of Sciences, 1974
- Arene Oxides: A New Aspect of Drug MetabolismScience, 1974
- Epoxides in Polycyclic Aromatic Hydrocarbon Metabolism and CarcinogenesisAdvances in Cancer Research, 1974
- Preferential induction of aryl hydroxylase activity in rat liver nuclear envelope by 3-methylcholanthreneBiochemical and Biophysical Research Communications, 1973