Thirty-five female Sprague-Dawley weanling rats were fed 5-acetamido-3-(5-nitro-2-furyl)-6H-l ,2,4-oxadiazine for 37 weeks. All 32 rats surviving 28 weeks or more developed hemangioendothelialsarcomas at one or more sites. These unusual tumors were located in the livers of 31 rats, in the mesentery of 30 rats, and in the lungs of 5 rats. Nine rats developed alveolar carcinomas, and 1 rat develo...
