[Cytogenetic characteristics of lung tumors induced by exposing BALB/C mice to transplacental N-nitrosoethylurea].

Chromosome pattern of lung adenocarcinomas in BALB/c mice exposed to N-nitrosoethylurea during prenatal life (transplacental action) was studied; it appeared that 121 of 145 metaphases examined contained 40 chromosomes. Along with this, there were revealed individual hypo-, hyperdiploid and tetraploid cells. Chromosomes possessed the usual telecentric structure in all the cells. The problem of possible changes of kariotypes of the tumours under study indetectable by the routine staining techniques is discussed.