Transplacental Blastomogenesis in Organ Cultures of Embryonic Lung Tissue

Urethan, nitrosomethylurea, and dimethylnitrosamine were studied to ascertain their transplacental and direct erfect on organ cultures of embryonic lung tissue of mice (strains A and C3HA) and rats (BD-IX). All the compounds greatly stimulated the growth of the explents and induced morphologic changes in them. The transplacental administration of urethan first induced irregular hyperplasia and focal growth of epithelium in the cultures and then adenomas. The first adenoma appeared the 4th day after explantation, and at 2 weeks adenomas were observed in 60% of the explants. Nitrosamines caused marked growth of epithelium in cultures, resulting in papillary adenomatosis which was observed both when administered transplacentally and when added immediately to the cultures in vitro as well as with the combined administration. The transplacental effect of nitrosomethylurea on the lung organ cultures from rats caused adenomatosis and presarcomatous growth. The organ culture method can be used to detect precancerous conditions and to test for rapid determination of the oncogenic activity of some chemical compounds.