[Relation of the blastomogenic effect of nitrosodimethylamine in rats to the method of its administration]

It is proved in experiments with the interrupting and twenty-four hour inhalations and peroral use of nitrosodimethylamine on the Wistar and white rats, that blastomogenic effect is submitted to the dose-effect dependence. On the whole the tumour incidence is determined by a total dose of carcinogen but its size may vary to a considerable extent depending on the regime of nitrosodimethylamine delivery. The daily and single doses of carcinogen are of great importance. Relatively high daily doses introduced within a short period of time cause a greater effect than low doses introduced within a larger period of time. The greater blastomogenic effect is caused by a longer peroral introduction of the same daily dose.