Transplacental effects of nitrosamines in Syrian hamsters. II. Nitrosopiperidine.

Nitrosopiperidine (NP) was found in Syrian hamsters quantitatively in the maternal blood for more than 8 h after subcutaneous injection, whereas it disappeared from placenta, fetus and amniotic fluid within the same time period. For N6MI, only traces were seen after 2 h in the same tissues. The long-term transplacental effect of a single dose of NP was weak, as demonstrated by a low respiratory tract tumor incidence (P-generation: 54%, F1- generation: 4%). Some tumors occurring in the digestive tract of exposed young were not found in their mothers and not commonly observed in controls. These tumors were considered a borderline transplacental effect. Tumors of other sites (i.e., the urogenital and genital tracts, reticuloendothelial system, endocrine organs and other tissues) corresponded in incidences to the overall fluctuations observed in this hamster colony.