[The effect of nitrofurazone and furazolidone on induction of cytochrome P-450 in the CYPIA test].
The double CYPIA-TEST (cytochrome P-450) induction assay) was used to discriminate 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 cyclophosphamide (CPA) for PB type of cytochrome P-450. The mutagenicity of activated EtBr and CPA was checked 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.