Ethylation of nucleic acids by ethylnitrosourea-1- 14 C in the fetal and adult rat.

The monofunctional alkylating agent jV-ethyl-TV-nitrosourea has become known as a highly potent transplacental pulse carcinogen, specifically directed against cells associated with the nervous system. In the present study, the formation of the alkylation product 7-ethylguanine in the nucleic acids of brain and liver of both fetal and adult BD-IX rats (18th day of gestation) was demonstrated by ion-exchange radiochromatography, after administration of jV-ethylW-nitrosourea-l-^C. One hr after i.v. injection of 75 fig of TV-ethyl-W-nitrosourea-l14C/g body weight (~30% of the 50% lethal dose), the