dietary-related indoles , isothiocyanates , and the allyl isothiocyanate glucosinolate , sinigrin , were administered to f344 rats in the diet for 2 weeks ( chronic protocol ) or by gavage 2 h before sacrifice ( acute protocol ) and the effects of these pretreatments on the alpha-hydroxylation of two carcinogenic nitrosamines , n-nitrosodimethylamine ( ndma ) and 4- ( methylnitrosamino ) -1- ( 3-pyridyl ) -1-butanone ( nnk ) , were evaluated . alpha-hydroxylation was measured in vitro by quantitation of formaldehyde formation upon incubation of the nitrosamines with liver microsomes , and in vivo by quantitation of levels of 7-methylguanine and o6-methylguanine in hepatic dna , 4 h after nitrosamine treatment .
C0012431
n-nitrosodimethylamine
C0028197
nitrosamine