Werner G. Jaffé, Ph.D.
CANCER RESEARCH, VOLUME 7, NUMBER 2, FEBRUARY 1947
One series of 57 rats was fed 0.15 per cent of ethyl urethane in the diet for 15 months. Fifty-nine per cent of the animals surviving more than 9 months developed pulmonary adenomas. Moreover, 1 case of an incipient hepatoma was found. Twenty-eight rats were injected 30 times with 100 mgm. of urethane and 7 per cent of the animals survviving more than 9 months after the first injection developed pulmonary adenomas; 25 per cent developed hepatomas within 15 months. Twenty-five rats received 1 intravenous injection of 2 mgm. of methylcholanthrene in olive oil and 3 O injections of 100 mgm. in an aqueous solution of urethane intraperitoneally; 9 per cent of these animals had pulmonary adenomas and 27 per cent had hepatomas after 15 months.