Experimental Studies on Ovarian Tumorigenesis

Part 1. Strain Difference of Ovarian Tumorigenesis in Mice Recieved Single Intravenous Injection of Emulsion of 7, 12-DMBA

Abstract

Induction of tumors with a single intravenous injection of 2.5mg of 7,12-Dimethylbenz(a)anthracene (DMBA) - 0.5 ml of emulsion - was investigated on the mice of C₃H, A/Jax, Strong A, C57Black, CBA, or AKR strain.
Any tumors were not found in the co ntrol, non - injected mice of these strains at the age of 9 - 11 months, in exception of few pulmonary tumor in the mice of A strain. The injection was performed at the age of 7 - 8 weeks. Seven - 9 months after the single injection, the following tumor incidences were obtained in the treated mice: Ovarian tumors were macroscopically found in 60 % of C₃H, and less 30 % of A/Jax, Strong A, and AKR mice. Pulmonary tumors were morphologically observed in all injected mice of A/Jax or Strong A strain, and in 75 % of AKR mice. Neither lymphoma, leukemia nor mammary tumor was detected in any mice examined.
Three fourth of the ovarian tum ors in C₃H mice showed histologically the arrangement of granulosa-cell tumor including undifferentiated and well-differentiated type. A half or two third of the ovarian tumors in the other strains were blood cysts with granulosa-cell proliferation. Induced lung tumors showed histologically papillary adenoma, similar to the later spontaneously developed pulmonary tumors in the mice of A strain.
In brief, ovarian tumor of granulosa-cell type was induced at the high incidence by DMBA only in C311 mice.