Effect of food restriction on the metabolism of dimethylnitrosamine (NDMA) in rats.
The influence of food restriction on the macromolecular interactions of the hepatocarcinogen dimethylnitrosamine (NDMA) in the livers of male Sprague Dawley rats was investigated. Two-three month old rats were food restricted (FR) (40% with respect to ad libitum fed rats) for three weeks. The liver weight, total protein, microsomal and cytoplasmic protein, cytochrome P-450 and DNA content per whole liver were all reduced significantly in food restricted rats. Five hours after a single dose of (14C) NDMA (28 mg/k.b.w., 21 microCi/rat) the levels of 7-methylguanine increased in restricted rats by 32%. Cytochrome P-450 mediated generation of HCHO from NDMA (1.8 fold) in restricted rats was greater. Binding of NDMA derived radioactivity to total hepatic proteins decreased by 46% in restricted rats. These results suggest that food restriction enhances the metabolic activation of dimethylnitrosamine in Sprague Dawley rats.
Prasanna
H R
HR
Fels Research Institute, Temple University School of Medicine, Philadelphia, PA 19140.
Hart
R W
RW
Magee
P N
PN
D000818:Animals; D001711:Biotransformation; D004247:DNA / Q000378:metabolism; D004038:Diet, Reducing; D004128:Dimethylnitrosamine / Q000378:metabolism*; D008099:Liver / Q000378:metabolism; D008297:Male; D008745:Methylation; D051381:Rats; D011919:Rats, Inbred Strains
D004247:DNA; D004128:Dimethylnitrosamine