Methylation of intestinal and hepatic DNA in rats treated with methylazoxymethanol acetate

✍ Scribed by Dr. Morris S. Zedeck; George B. Brown

• Publisher: John Wiley and Sons
• Year: 1977
• Tongue: English
• Weight: 658 KB
• Volume: 40
• Category: Article
• ISSN: 0008-543X
• DOI: 10.1002/1097-0142(197711)40:5+<2580::aid-cncr2820400929>3.0.co;2-z

✦ Synopsis

Descending colon is the most unsitive segment of rat intestine and is at least as ynsitive as liver to the carcinogenic effectr of methylazoxymethanol acetate. To determine whether a relationship esistr between tumor induction and level of DNA methylation, we measured the levels of 7-methylguanine in the DNA isolated from duodenum, descending colon, and liver of rats treated with this carcinogen. Because radiolabeled methylazoxymethanol acetate is not available, we utilized high pressure liquid chromatography whereby methylated purines could be detected in amounts as little as 100-300 pmoler. DNA isolated from liver of carcinogen-treated rats had significant amounts of 7-methylguanine. O n the contrary, DNA irolated from descending colon of rats treated with methylazoxymethanol acetate had minimal amounts of 7-methylguanine; these data suggest that the level of 7-methylguanine does not correlate with sensitivity to tumor induction by methylazoxymethanol acetate.