title: Induction of digestive-tract tumors in F344 rats by continuous oral administration of N-butyl-N-nitrosourea.
abstract: Male and female F344/DuCrj rats were administered N-butyl-N-nitrosourea at a concentration of 400 ppm in their drinking water. By the 50th week of the experiment, the cumulative incidence of upper-digestive-tract tumors was as high as 35/39 (90%) and 34/39 (87%) in male and female rats, respectively. Among these, esophageal and forestomach tumors occurred most frequently. Except one female rat with fibroma, upper-digestive-tract neoplasms were of the epithelial type -- papilloma, squamous-cell carcinoma or adenocarcinoma. In female rats, vaginal tumors were induced in 16 (41%) animals. Ear-duct tumors and hematopoietic neoplasms were also induced in both sexes of rats, with incidence of less than 21%.
mesh_terms: D000230:Adenocarcinoma / Q000139:chemically induced; D000818:Animals; D002294:Carcinoma, Squamous Cell / Q000139:chemically induced; D004067:Digestive System Neoplasms / Q000139:chemically induced* / Q000473:pathology; D004326:Drinking; D004428:Ear Neoplasms / Q000139:chemically induced; D005260:Female; D007414:Intestinal Neoplasms / Q000139:chemically induced; D007938:Leukemia / Q000139:chemically induced; D008297:Male; D009607:Nitrosourea Compounds / Q000008:administration & dosage*; D010212:Papilloma / Q000139:chemically induced; D051381:Rats; D011916:Rats, Inbred F344; D013997:Time Factors; D014625:Vaginal Neoplasms / Q000139:chemically induced
chemical_list: D009607:Nitrosourea Compounds; C002738:N-nitrosobutylurea