Hyperplastic Nodules and Adenomas of Exocrine Pancreas in Azaserine-Treated Rats2

Abstract

Long-term studies of the carcinogenicity of azaserine in rats were undertaken to develop a model of adenocarcinoma of the pancreas. Rats were treated for 6 weeks to 6 months with once or twice weekly intraperitoneal azaserine injections. Single doses were 5–25 mg/kg; total doses were 120–300 mg/kg. All of 18 rats autopsied 3½, 6, or 8 months after initiation of treatment had nodular groups of atypical exocrine cells which seemed to represent hyperplastic foci, and 3 rats had small exocrine adenomas. No malignant tumors were found. One of 6 control rats contained 1 hyperplastic nodule in exocrine pancreas.