The bovine pancreatic ductal explant model has been shown to be an excellent system to study pancreatic chemical carcinogenesis. Exposure of the explants to nitroso compounds such as dimethylnitrosamine, N-methyl-N-nitroso-N'-nitroguanidine and others have produced morphological alteration suggestive of adenocarcinoma. Ultrastructural studies on treated explants demonstrated such changes as the presence of large nucleoli with some evidence of microsegregation, an increase in the nucleo to cytoplasmic ratio as well as other atypical alterations. The purpose of the proposed research is to determine if the lesions produced in the bovine pancreatic explant model are malignant by xenotransplantation techniques, growth in salt agar, as well as further studies of the explants by biochemical and morphological means. Techniques will also be developed in order to culture Syrian hamster pancreatic ducts.