In vitro and in vivo DNA interaction with carbonyl-labeled (m)ethylnitrosoureas

1. The carbonyl group of (m)ethyylnitrosoureas was found to interact with DNA both in vitro and in vivo. 2. (14C-carbonyl)radioactivity remained associated to DNA after a number of ethanolic precipitations as well as after RNase and protein digestion treatments, but was extremely labile to DNA enzymic and acid digestion. 3. Detectable amount of (14C-carbonyl)-radioactivity was still found in DNA of various rat tissues 18 days after i.p. administration of carbonyl-labeled methylnitrosourea.