Abstract
1. The metabolism of 4-ethynylbiphenyl has been studied in vitro with subcellular fractions of normal and induced rat liver, and rat intestinal microflora (caecal contents). 2. Oxidation was NADPH-dependent, was inhibited by CO and stimulated by pretreatment with phenobarbitone or 3-methylcholanthrene. 3. Oxidation of the ethynyl group occurred in washed microsomal preparations, but not significantly in soluble fractions. Oxidation of the ethynyl group by a microsomal fraction preceded aromatic hydroxylation and no metabolites containing the intact ethynyl group were detected. 4. The major metabolite in liver fractions was biphenyl-4-ylacetic acid. This was the only product produced by a modified Udenfriend system. 5. Metabolism of 4-ethynylbiphenyl by rat caecal contents under anaerobic conditions produced very small amounts of 4-vinylbiphenyl. 6. In a modified Ames test with Salmonella typhimurium TA98, 4-ethynylbiphenyl gave a weak positive result that was doubled after 'activation' with an induced rat S9 fraction.
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- Ames B. N., Mccann J., Yamasaki E. Methods for detecting carcinogens and mutagens with the Salmonella/mammalian-microsome mutagenicity test. Mutat Res. 1975 Dec;31(6):347–364. doi: 10.1016/0165-1161(75)90046-1. [DOI] [PubMed] [Google Scholar]
- Daly J. W., Jerina D. M., Witkop B. Arene oxides and the NIH shift: the metabolism, toxicity and carcinogenicity of aromatic compounds. Experientia. 1972 Oct 15;28(10):1129–1149. doi: 10.1007/BF01946135. [DOI] [PubMed] [Google Scholar]
- Dilworth M. J. Acetylene reduction by nitrogen-fixing preparations from Clostridium pasteurianum. Biochim Biophys Acta. 1966 Oct 31;127(2):285–294. doi: 10.1016/0304-4165(66)90383-7. [DOI] [PubMed] [Google Scholar]
- EL MASRI A. M., SMITH J. N., WILLIAMS R. T. Studies in detoxication. 73. The metabolism of alkylbenzenes: phenylacetylene and phenylethylene (styrene). Biochem J. 1958 Feb;68(2):199–204. doi: 10.1042/bj0680199. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lindeke B., Hallström G., Anderson E. Enzymic oxidation alpha to the acetylenic group in the metabolism of N-(5-pyrrolidinopent-3-ynyl)-succinimide (BL 14) in vitro. Xenobiotica. 1978 Jun;8(6):341–348. doi: 10.3109/00498257809070017. [DOI] [PubMed] [Google Scholar]
- Oesch F. Mammalian epoxide hydrases: inducible enzymes catalysing the inactivation of carcinogenic and cytotoxic metabolites derived from aromatic and olefinic compounds. Xenobiotica. 1973 May;3(5):305–340. doi: 10.3109/00498257309151525. [DOI] [PubMed] [Google Scholar]
- Scheline R. R. Decarboxylation and demethylation of some phenolic benzoic acid derivatives by rat caecal contents. J Pharm Pharmacol. 1966 Oct;18(10):664–669. doi: 10.1111/j.2042-7158.1966.tb07780.x. [DOI] [PubMed] [Google Scholar]
- UDENFRIEND S., CLARK C. T., AXELROD J., BRODIE B. B. Ascorbic acid in aromatic hydroxylation. I. A model system for aromatic hydroxylation. J Biol Chem. 1954 Jun;208(2):731–739. [PubMed] [Google Scholar]
- Wade A., Symons A. M., Martin L., Parke D. V. Metabolic oxidation of the ethynyl group in 4-ethynylbiphenyl. Biochem J. 1979 Dec 15;184(3):509–517. doi: 10.1042/bj1840509. [DOI] [PMC free article] [PubMed] [Google Scholar]
- White I. N. Metabolic activation of acetylenic substituents to derivatives in the rat causing the loss of hepatic cytochrome P-450 and haem. Biochem J. 1978 Sep 15;174(3):853–861. doi: 10.1042/bj1740853. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wood P., English J., Chakraborty J., Hinton R. The use of non-ionic industrial detergents in liquid scintillation counting. Lab Pract. 1975 Nov;24(11):739–740. [PubMed] [Google Scholar]