SPERMIDINE SPERMINE N-1-ACETYLTRANSFERASE AS A MARKER OF DIMETHYLHYDRAZINE-INDUCED COLONIC CARCINOGENESIS IN THE RAT/

We investigated whether spermidine/spermine N-1-acetyltransferase (SSA T) might be a useful marker of 1,2-dimethylhydrazine (DMH)-induced col orectal tumors in rats. Male Wistar rats were given DMH weekly for 5 w eeks (150 mg/kg/dose), and then sacrificed 5, 10, 15 or 20 weeks after the first dose. Tumors were detected in 2 of 6 rats sacrificed at 10 weeks. Colorectal mucosal SSAT activity was 25.8+/-2.4 pmoles/mg/min b efore dosing, and only slightly higher at 5 weeks (36.8+/-10.0). From week 5 onward, activity rose sharply and significantly, reaching 87.2/-29.0 by week 20. These results indicate that SSAT is an excellent ma rker of DMH-induced colonic carcinogenesis.