Development of adenocarcinomas after transplantation of rat glandular stomachs treated in vitro with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG).

Glandular stomachs of fetal and newborn Wistar rats were transplanted s.c. after treatment in vitro with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) at concentrations of 10, 5 and 1 microgram/ml for 2 h. Eleven adenocarcinomas developed from 118 MNNG-treated transplants, whereas no adenocarcinomas developed from 28 untreated transplants. The incidence of adenocarcinomas in fetal glandular stomach (9/46) was significantly different (p less than 0.01) from that in glandular stomach of newborn rats (2/67). Various types of mesenchymal tumors also developed from untreated (9/28) and MNNG-treated (20/118) transplants.