Abstract
Urethane has been known for its transplacental carcinogenic effect in mice. Whether or not the treatment of urethane affects embryonic growth and development and induces chromosome aberrations in the embryonic cells in vitro was investigated using the mouse whole embryo culture method. Reports on experiments in vivo showed that lungs and liver were target organs of carcinogenic effects of urethane. In the present experiment, organ (lung and liver)-specific susceptibility to clastogenic effect of urethane was observed in cultured embryonic cells. Further, it is stressed that urethane induced chromosome breaks at concentrations lower than the threshold value for the retardation on embryonic growth and development. Comparing with clastogenic effect of 4NQO on cultured embryonic cells, the clastogenic action of urethane was examined to point out its characteristic feature as a clastogen with special reference to the carcinogenic effects obtained by in vivo experiment.
