Vinyl acetate, a structural analog of vinyl carbamate, fails to induce enzyme-altered foci in rat liver

The development of hepatic enzyme-altered foci (ATPase, GGTase)was investigated after dosing vinyl acetate (200 and 400 mg/kgper day, orally) to newborn rats for 3 weeks, with or withoutsubsequent promotion by phenobarbital. Whereas the structurallyrelated compounds vinyl carbamate and vinyl chloride induceenzyme-altered foci under comparable experimental conditions,no foci were observed in vinyl acetatetreated animals at theage of 14 weeks. This is consistent with investigations on metabolismand pharmacokinetics of vinyl acetate which show that this compound,after entering the organism, is immediately split by blood esterasesand thus may not be available for epoxidation to an ultimatelycarcinogenic metabolite.