Scanning electron microscopical investigations on the respiratory epithelium of the Syrian golden hamster: transplacental effects of vinylethylnitrosamine.

The transplacental effect of vinylethylnitrosamine (VEN) on the respiratory epithelium of Syrian golden hamsters was tested after administration of 5 and 10 mg VEN/kg b.w. dissolved in olive oil at the 12th or 15th day of gestation. The morphological data, obtained mainly by scanning electron microscopy on tracheae revealed metaplastic and hyperplastic epithelial changes, as well as focal exophytic papillary proliferations at the 30th postnatal day in the group treated at the 15th day of gestation. No comparable lesions were found in the trachea of the F1 generation when mothers were treated with VEN at day 12 of pregnancy or in animals of the control group (olive oil only). The biological effects of VEN after transplacental exposure were compared to those of other nitrosamines.