title: Induction of tumors of the forestomach in rats by oral application of N-methyl-N'-nitro-nitrosoguanidine.
abstract: After 12 oral applications of 80 mg/kg MNNG as a suspension in 30% aqueous ethanol at weekly intervals, 98 Sprague-Dawley rats died with multiple tumors of the forestomach after a medium latency period of 226 days. Histological examination showed generalized papillomatosis developing into keratinizing squamous cell carcinomas with infiltrative growth in 88/98 (89%) animals. Tumorigenic lesions in the glandular stomach ware only observed in 3/98 rats. In two of these animals, mucosal adenocarcinomas were found and in the third a leiomyosarcoma. In about 30% of the animals treated with MNNG, degenerative liver changes were found, especially single cell and focal necroses, cystic alterations, and bile-duct proliferations.
mesh_terms: D000230:Adenocarcinoma / Q000139:chemically induced; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced / Q000473:pathology; D007890:Leiomyosarcoma / Q000139:chemically induced; D008099:Liver / Q000187:drug effects / Q000473:pathology; D008769:Methylnitronitrosoguanidine; D009374:Neoplasms, Experimental / Q000139:chemically induced; D010212:Papilloma / Q000139:chemically induced / Q000473:pathology; D051381:Rats; D011919:Rats, Inbred Strains; D013274:Stomach Neoplasms / Q000139:chemically induced* / Q000473:pathology
chemical_list: D008769:Methylnitronitrosoguanidine