Modifying effects of the enzyme inducers, phenobarbital and 3-methylcholanthrene, on dominant lethal events induced by 7, 12-dimethylbenz[a]anthracene in mice

The effects of pretreatment with either phenobarbital (PB) or 3-methylcholanthrene (MC) on the induction of dominant lethal events by 7, 12-dimethylbenza]anthracene (DMBA) in male mice were studied. DMBA induced dominant lethals in both post- and pre-meiotic germ cells of mice. The incidences of DMBA-induced dominant lethals were markedly reduced in pre-meiotic germ cells by the pretreatment with PB, whereas a significant reduction of the lethal events in post-meiotic germ cells was observed with MC. No significant reduction of living implants was detected in pre-meiotic germ cells on pretreatment with PB. The contents of liver microsomal cytochrome p-450 of mice pretreated with PB or MC were about twice those of non-treated mice.