Carcinogenesis in Sprague-Dawley rats of N-nitroso-N-alkylcarbamate esters.
Nitrosocarbaryl, nitroso-N-methylurethane and nitroso-N-ethylurethane were administered by gavage in olive oil solution to groups of 12 female Sprague-Dawley rats. The dose was 0.2 ml of 0.11 M solution once a week for 10 weeks, a total dose of 0.22 mmol. The rats given nitrosocarbaryl survived longer, but had as high an incidence of tumors (75%) as did rats given nitrosomethylurethane. Most of the tumors induced were invasive squamous carcinomas of the stomach. Nitrosoethylurethane appeared to be a little more potent than nitrosomethylurethane; all 12 animals in this group had squamous stomach tumors at death. A higher total dose of nitrosocarbaryl, 1.3 mmol, given to male rats twice weekly for 20 weeks did not produce a higher incidence of stomach tumors than did thelower dose in females, although the males died earlier with tumors.
D000284:Administration, Oral; D000287:Administration, Topical; D000818:Animals; D012721:Carbaryl / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000633:toxicity; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced*; D005260:Female; D009374:Neoplasms, Experimental / Q000139:chemically induced; D009602:Nitrosamines; D009603:Nitroso Compounds / Q000008:administration & dosage / Q000633:toxicity*; D009605:Nitrosomethylurethane / Q000031:analogs & derivatives* / Q000633:toxicity*; D051381:Rats; D012878:Skin Neoplasms / Q000139:chemically induced; D013274:Stomach Neoplasms / Q000139:chemically induced*; D014520:Urethane / Q000031:analogs & derivatives*
D009602:Nitrosamines; D009603:Nitroso Compounds; D014520:Urethane; D009605:Nitrosomethylurethane; C008649:nitrosocarbaryl; D012721:Carbaryl