Tumorigenic action of streptozotocin on the pancreas and kidney in male Wistar rats.

Pancreatic islet cell tumors were induced in 38 of 44 male Wistar rats (86%), which survived 9 to 14 months following the various treatment schedules. A single i.v. injection of streptozotocin alone, 30, 40, 50, or 65 mg/kg of body weight produced adenomas of pancreatic islet cells in 8 of 9 (89%), 6 of 7 (86%), 2 of 4 (50%), and 1 of 2 rats (50%), respectively. The neoplasms were seen in all of the 8 rats given a single i.p. injection of picolinamide, 250 mg/kg of body weight, 15 min before a single i.v. injection of streptozotocin, 65 mg/kg of body weight. Among the 14 rats given a single i.p. injection of nicotinamide, 500 mg/kg of body weight, 15 min before a single i.v. injection of streptozotocin, 65 mg/kg of body weight, 13 rats (95%) developed pancreatic islet cell tumors. Renal tumors were seen in only 3 rats treated with streptozotocin and nicotinamide. None of rats used in this study developed hepatic tumors. This study demonstrates that steptozotocin, even in a dose of 30 mg/kg of body weight, has an exceedingly marked tumorigenic action on the rat pancreas, while it has little effect on the kidney and no effect on the liver.