[Blastomogenesis in repeated administration of DMBA in rats during different life periods]

Three groups of rats were given DMBA emulsion during different periods of the life. The first group received the carcinogen transplacentally, the second- at the age of three months, the third was given the agent twice during the mentioned terms. The third group showed a summation of the blastomogenic effect which was manifested in the frequency of tumors, including neurogenic, renal and mammary gland tumors, in the index of neoplasms multiplicity as well as in shorter average life terms. The results were compared with pure control findings.