INDUCTION OF INTESTINAL METAPLASIA AND CARCINOMA IN THE GLANDULAR STOMACH OF RATS BY N-ALKYL-N'-NITRO-N-NITROSOGUANIDINES

Induction of intestinal metaplasia and carcinoma of the stomach in Wistar rats by four homologs of N-alkyl-N'-nitro-N-nitrosoguanidine (N-alkyl-NNG) was investigated. N-Propyl-, N-butyl-, N-isobutyl, and N-pentyl-NNG's were administered to rats as 0.34mM solutions in the drinking water for 12 months and the rats were killed about 6 months later. Intestinal metaplasia was found in the glandular stomach of 100%, 50%, 44%, and 17% of the rats treated with N-propyl-, N-butyl-, N-isobutyl-, and N-pentyl-NNG's, respectively. Adenocarcinoma of the glandular stomach was found in 29% of the rats treated with N-propyl-NNG, but not in those treated with other N-alkyl-NNG's. In the control group, 11% of the rats had intestinal metaplasia but none had tumors.