[An experimental study on the development of myleran-induced oligodactyly in rats].

The same type of preaxial oligodactyly appeared in all new born rats when a Wistar rat was treated with myleran on the 12th day of gestation in this experiment. In order to clarify the mechanism of this type of oligodactyly, the development of digital formation and the extent and location of the tissue damage in the hand plate were examined histologically. The preaxial ectoderm of the hand plate was specifically damaged in the early stage of gestation from the 12th and a half to the 13th day. On the other hand, the mesoderm of the hand plate was diffusely damaged at the same time. Condensation of mesodermal cell never occurred in the preaxial part of the mesoderm corresponding to the damaged ectoderm. The finding obtained in this study strongly indicate that disorder of ectoderm-mesoderm interaction may play a role in the development of the oligodactyly produced by myleran.