title: Retention of promutagenic O6-ethylguanine in the DNA of various rat tissues following transplacental inoculation with ethylnitrosourea.
abstract: Pregnant Fischer rats at their 20th day of gestation were inoculated intravenously with [14C]ENU (75 mg/kg). The O6-ethylguanine content of liver, kidney, and brain DNA from both fetuses (offspring) and adults were quantitatively determined 3 h and 7 days after carcinogen treatment. Removal of O6-ethylguanine from the DNA of brain (target) was much slower than from liver (non-target) and kidney (low-target). Retention of O6-ethylguanine was found to be relatively similar in adult and fetal brains, although 100% of the offspring transplacentally exposed to 75 mg/kg ENU were shown to develop tumors of the nervous system, whereas the inoculated pregnant dams did not.
mesh_terms: D000478:Alkylation; D000818:Animals; D001921:Brain / Q000378:metabolism; D004247:DNA / Q000378:metabolism*; D004261:DNA Replication; D005038:Ethylnitrosourea / Q000378:metabolism*; D005260:Female; D006147:Guanine / Q000031:analogs & derivatives* / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008431:Maternal-Fetal Exchange; D009374:Neoplasms, Experimental / Q000139:chemically induced; D009607:Nitrosourea Compounds / Q000378:metabolism*; D011247:Pregnancy; D051381:Rats
chemical_list: D009607:Nitrosourea Compounds; C007673:6-ethylguanine; D006147:Guanine; D004247:DNA; D005038:Ethylnitrosourea