In order to develop a high-frequency, single-dose model of renal epithelial tumor induction in the mouse, streptozotocin (250 mg/kg) was administered i.v. to 6-week-old males and females of the CBA/H/T6J strain. In groups of 26 males and 30 females representing the effective number of survivors eligible for tumor estimates, renal cell tumors were found in 73% of males and 97% of females, including incidences of lesions diagnosed as renal carcinoma in 31 and 60%, respectively. The difference in

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... enal tumor frequency between the sexes was not considered a real effect owing to the significantly decreased survival of the males. The neoplastic lesions ranged from small papillary or cystopapillary adenomas with a benign appearance to large, solid carcinomas with a low potential for metastasis. In the females, 22% of the larger tumors metastasized to distant sites, mainly the lungs. Intermediate lesions incorporating both papillary and solid adenomatous profiles suggested a sequential development of carcinomas along this pathway from the smaller papillary foci. The data establish the administration of a single dose of streptozotocin in the female CBA/H/T6J as a suitable high incidence model for the study of renal epithelial carcinogenesis in the mouse.