CARCINOGENICITY IN RATS OF NITROSOMETHYLETHYLAMINES LABELED WITH DEUTERIUM IN SEVERAL POSITIONS

Abstract

Nitrosomethylethylamine and 4 of its derivatives labeled with deuterium at various positions were administered to male Fischer 344 rats in drinking water at equimolar doses for 30 wk. The doses were 30 and 6 mg/l at the rate of .apprx. 3 and 0.6 mg/wk. The rats receiving the higher doses died earlier and had more tumors than those given the lower doses. At both dose levels, nitrosomethylethyl-1-d2-amine and nitrosomethylethyl-d5-amine were more effective carcinogens than was unsubstituted nitrosomethylethylamine. Rats died earlier, and more of them had tumors after receiving the deuterium-labeled compounds. Nitrosomethyl-d3-ethylamine and nitrosomethyl-d3-ethyl-d5-amine did not greatly differ in carcinogenic effectiveness from the unsubstituted compound. Both nitrosamines having deuterium in the methyl portion of the ethyl group, nitrosomethylethyl-d5-amine and nitrosomethyl-d3-ethyl-d5-amine, induced esophageal tumors as well as liver tumors in the rats.