[Effect of different doses of ascorbic acid on the induction of tumors with N-nitroso compound precursors in mice].

Experiments used 409 male CBA mice to study the effect of ascorbic acid on carcinogenesis induced by treatment with such precursors of nitroso compounds as sodium nitrite and morpholine. The former was given with feed in a total dose of 573-891 mg/animal and the latter--with drinking water in a total dose of 138-183 mg/animal. As a result, the total number of tumor-bearers grew from 63.8% (controls) to 82.5%. Treatment with all doses of ascorbic acid tested (1.5; 0.25 and 0.025% with drinking water) was followed by reduction in frequency of tumors in animals treated with nitroso compound precursors to 37.9, 55.1 and 60%, respectively.