Detection of mutagenicity of procarbazine by the host-mediated assay with polychlorinated biphenyl (aroclor 1254) as enzyme inducer.

Procarbazine [N-isoppropyl-alpha-(2-methylhydrazino)-p-toluamide] was tested for mutagenicity with Salmonella typhimurium G46 in the host-mediated assay by using male BALB/c mice pretreated orally with polychlorinated biphenyl (PCB, Aroclor 1254). Procarbazine was weakly mutagenic without PCB pretreatment, but the pretreatment greatly enhanced the mutagenicity of this compound. The administration of 500 mg PCB/kg 1 day before procarbazine dosage was suitable for the detection of the mutagenicity. Among PCB, 3-methylcholanthrene (3-MC) and phenobarbital sodium (PB), the former 2 inducers showed much stronger enhancing effects than PB. The pretreatment with 3-MC in combination with PB did not cause further enhancement compared with 3-MC alone.