Carcinogenicity of 2-amino-4-(5-nitro-2-furyl)thiazole in rats by oral and subcutaneous administration

Female Fischer rats were divided into two groups and fed eitherbasal diet or basal diet containing 0.166% 2-amino-4-(5-nitro-2-furyl)thiazolefor 52 weeks followed by basal diet for an additional 16 weeks.Out of the 24 rats fed 2-amino-4-(5-nitro-2-furyl)thiazole,23 had forestomach tumors, four had fibroadenomas and two hadadenocarcinomas in the mammary glands, two had renal pelviccarcinomas, five had papillomas and six had carcinomas in thebladder, and two had cutaneous tumors. None of the 10 rats fedbasal diet developed tumors. In another study, two-week-oldFischer rats of both sexes were injected s.c. once a week forthe first eight weeks with 2-amino-4-(5-nitro-2-furyl)thiazoleat a dose of 10 mg/kg and then 1.4 mg/rat for an additional46 weeks. The control rats were injected with solvent (dimethylsulfoxide:water, 1: 1) only. The experiment was terminated atthe end of 58 weeks. Malignant fibrous histiocytomas were foundin five out of eight male rats and four out of 11 female rats,and an angiosarcoma was found in one out of eight male ratsinjected with 2-amino-4-(5-nitro-2-furyl)thiazole. None of thecontrol rats developed tumors.