1,2-Dimethylhydrazine carcinogenesis in CBA male mice prenatally treated with diethylstilbestrol.

CBA female mice, at the 17th day of pregnancy, received single intraperitoneal injection of diethylstilbestrol (DES) at the dose of 1 mg/kg body weight (b. w.). Their descentands at the age of 2 months started receiving subcutaneous injections of 1,2-dimethylhydrazine (DMH) at the dose level of 8 mg(base)/kg b. w., total 15 weekly injections. Prenatal DES treatment of male mice considerably accelerated the development and increased the incidence of DMH-induced androgen-dependent renal adenomas and, notably, renal capsule angiosarcomas (RCA). In males receiving prenatal DES (without subsequent DMH-treatment), there was a statistically significant increase of renal adenomas and 9% of RCA were observed which are exceedinly rare in untreated mice. The enhancement of androgen-dependent tumourigenesis may be considered as an indication, even though indirect, of the hyperandrogenization produced in male mice by the prenatal DES treatment.