Species Difference in the Ovarian Toxicity of 1,3-Butadiene Epoxides in B6C3F sub(1) Mice and Sprague-Dawley Rats

Ovarian cancer is caused by 1,3-butadiene exposure in mice, but such exposure does not affect rat ovaries. Female rats and mice were injected with various concentrations of the 1,3-butadiene metabolites, butadiene monoepoxide, or butadiene diepoxide for 30 days. The next day the animals were sacrificed. Mice exposed to butadiene monoepoxide had reduced reproductive organ weights, and numbers of follicles. These parameters remained normal in monoepoxide-exposed rats. Both species demonstrated reductions in weight of ovaries and uteri after exposure to butadiene diepoxide. Follicular population was reduced in both species, but mice were more severely affected than rats.