ABSTRACT

The double CYPIA-TEST (cytochrome P-450 induction assay) was used to descriminate between the forms of cytochrome P-450 (the 3-methylcholantrene type (3-MC) or phenobarbital type (PB)) induced by nitrofurans; nitrofurazone and furazolidone. The test consisted of the studies by the technique of Ames of the ability of the S9 preparation obtained from livers of rats induced by nitrofurans to cause the metabolic activation of ethidium bromide (EtBr) - for induction of 3-MC type or cyclphosphamide (CPA) for PB type of cytochrome P-450. The mutagenicity of activated EtBr and CPA was chicked with TA98 and TA100 of S. typhimurium respectively. It was found that only furazolidone at cumulative dose 3 x 80 mg/kg of body weight induce -the 3-MC-type of cytochrome P-450.