title: The carcinogenicity of 1-methyl-3(p-bromophenyl)-1-nitrosourea (Br-MPNU).
abstract: In long-term experiments with Hooded rats the carcinogenic potential of 1-methyl-3(p-bromophenyl)-1-nitrosourea (Br-MPNU) could be demonstrated for the first time. Br-MPNU is formed also endogenously after combined administration of 1-methyl-3(p-bromophenyl)-urea (Br-MPU) and sodium nitrite. After repeated intragastric administration of 0.33 mmol Br-MPU and 0.73 mmol NaNO2 per kg b.w. papillomas and carcinomas of the forestomach developed in 83%. After repeated administration of 0.28 mmol Br-MPNU per kg b.w. these neoplasms were observed in 88%. The comparison of results obtained in similar experiments with 1-methyl-3-phenyl-1-nitrosourea shows that bromine substitution led to a reduction of the carcinogenic activity. The present paper is part of a complex program studying the interrelationships between structure, physico-chemical properties, mutagenicity and carcinogenicity of nitrosoureas.
mesh_terms: D000284:Administration, Oral; D000818:Animals; D002273:Carcinogens / Q000633:toxicity*; D004347:Drug Interactions; D005260:Female; D008297:Male; D009374:Neoplasms, Experimental / Q000139:chemically induced*; D009607:Nitrosourea Compounds / Q000008:administration & dosage / Q000633:toxicity*; D010671:Phenylurea Compounds / Q000633:toxicity; D051381:Rats; D011919:Rats, Inbred Strains; D012977:Sodium Nitrite / Q000633:toxicity; D013274:Stomach Neoplasms / Q000139:chemically induced; D013997:Time Factors
chemical_list: D002273:Carcinogens; D009607:Nitrosourea Compounds; D010671:Phenylurea Compounds; C039338:1-methyl-3-(4-bromophenyl)urea; C039337:1-methyl-3-(4-bromophenyl)-1-nitrosourea; D012977:Sodium Nitrite