Increase of urinary putrescine in 3,4-benzopyrene carcinogenesis and its inhibition by putrescine.

A significant increase in putrescine was noted in the urine of mice with experimental s.c. tumors induced by a single injection of 3,4-benzopyrene solution (2.52 mg of 3,4-benzopyrene in 0.5 ml of tricaprylin). When 10 mg of putrescine were added to the 3,4-benzopyrene solution, the development of tumors was completely inhibited and the increase of urinary putrescine in mice was suppressed simultaneously. Animal weight data of a control group receiving only putrescine indicated that the inhibitory effect of putrescine is not due to its toxicity.