SOME RESULTS AND PROSPECTS OF TRANSPLACENTAL CARCINOGENESIS STUDIES

  • 1 January 1976
    • journal article
    • research article
    • Vol. 23  (3) , 285-299
Abstract
Analysis of literary data and the present findings showed that the transplacental action of most of the compounds tested in rats manifested itself by a neurotropic carcinogenic effect. A marked neurotropism in transplacental carcinogenesis in rats is characteristic even for such carcinogens (e.g., dimethylbenzanthracene) that never induced neurogenic neoplasms in adult animals. To elucidate the relationship between teratogenesis and carcinogenesis the peculiarities of tumor development in brain against the background of malformations induced by combined transplacental treatment with methylnitrosourea (MNU) and ethylnitrosourea (ENU) in rats were studied. Tumorigenesis was sharply inhibited by administration of ENU (on the 13th day) prior to MNU treatment (on the 15th day). The cytotoxic effect of MNU for microcephaly results in the death of a considerable part of the cell population already transformed by ENU. In a special series of experiments, characteristics of the permeability of polycyclic aromatic hydrocarbons through the placenta in rats were specified.