Mechanism of Fusarium mycotoxin action in mammary gland.

The interaction of the Fusarium mycotoxins zearalenone and dihydrozearalanol with specific estrogen binding sites was studied by using cytosol preparations of mammary glands from lactating rats. Both substance inhibited [3H] estradiol-17beta association with its binding site in a competitive fashion. This inhibition was a result principally of an effect on estrogen binding by the 8S species of receptors separated by density gradient centrifugation. These data suggest that the biological action of Fusarium mycotoxins with estrogenic activity is mediated by intracellular estrogen receptors.