Reduced accumulation of I-compounds in liver DNA of rats fed a choline-devoid diet.
Groups of rats were fed for 1, 4 or 7 months choline-devoid or choline-supplemented diets, that provided approximately 50% of the methionine, and 0.15% or 150% of the choline requirements of young, growing rats. Liver DNA was isolated and analyzed by the nuclease P1-enhanced version of the 32P-postlabeling assay, which detects aromatic/hydrophobic DNA adducts and I-compounds (adduct-like DNA modifications shown to accumulate in tissue of aging rats). DNA adducts and qualitative differences in the patterns of I-compounds were not observed in rats fed the two diets. However, in rats fed the choline-devoid diet there was a drastic reduction in the accumulation of I-compounds, compared with that in rats fed the control diet. These results extend previous evidence of a lack of relevant DNA adducts in the liver of rats fed the choline-devoid diet, and suggest the possibility of a role of I-compounds in the carcinogenicity of this diet.
Li
D
D
Department of Pharmacology, Baylor College of Medicine, Houston, TX 77030.
Chandar
N
N
Lombardi
B
B
Randerath
K
K
D000818:Animals; D002796:Choline Deficiency / Q000378:metabolism*; D004247:DNA / Q000378:metabolism*; D015227:Lipid Peroxidation; D008099:Liver / Q000378:metabolism*; D008297:Male; D051381:Rats; D011916:Rats, Inbred F344
D004247:DNA