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1987
Book Article
Titel
Transplacental carcinogenesis, mouse, rat, hamster
Abstract
In spite of a statement made in older textbooks that the placenta forms a protective barrier for the embryo and fetus, today we can state with certainty that most hemicals, many viruses, and even some blood cells, are transferrred through the placenta and may cause diseases in the offspring. Cancer can also be induced by compounds transferred across the placenta during the prenatal period. In 1940, law demonstrated that pulmonary tumors developed in F-1 mices which received directintrauterine exposure to dibenzanthracene. Larsen (1947) demonstrated the induction of lung tumors in the offspring of pregnant mice after urethan treatment between the 2nd and 18th day of pregnancy. The results of this work initially met with some skepticism because of the high spontaneous rate of lung tumors in this species (Shay et al. 1952; Smith and Rous 1948). No further work was carrier out on transplacental carcinogenisis until 1964, when Mohr and coworkers clearly demonstrated that diethylnitrosamin e was tumorigenic in the respiratory tract of Syrian hamsters after transplacental exposure. The results of these experiments are even more impressive because spontaneous tumors in the respiratory tract of the hamster are very rare (1-1000 animals). Furthermore a number of experiments have proved the transplacental passage of diethylnitrosamine and other carcinogens (Mohr et al. 1980; Alexandrov 1983)