Administration of N-nitrosodimethylamine, N-nitrosopyrrolidine, or N'-nitrosonornicotine to nursing rats: their interactions with liver and kidney nucleic acids from sucklings.

When nursing Sprague-Dawley rats were treated with [14C]N-nitrosodimethylamine [(NDMA) CAS: 62-75-9], N-nitrosopyrrolidine (CAS:930-55-2), or N'-nitrosonornicotine (CAS: 16543-55-8), the liver and kidney DNA from their 14-day-old offspring that had been nursed over a 24-hour period became labeled. Upon analysis, liver DNA from sucklings whose nursing mothers were treated with [14C]NDMA showed N7-methylguanine- and O6-methylguanine-altered bases. The results suggest that these nitrosamines, which are present in food, tobacco smoke, and in different environmental sources, are a risk not only for lactating mothers but also for the nursing infants.