Relative Binding Affinity-Serum Modified Access (RBA-SMA) Assay Predicts the Relative In Vivo Bioactivity of the Xenoestrogens Bisphenol A and Octylphenol

摘要

We have developed a relative binding affinity-serum modified access (RBA-SMA) assay to deter- mine the effect of serum on the access of xenoestrogens to estrogen receptors within intact cul- tured MCF-7 human breast cancer cells. We used this assay to predict low dose activity of two xenoestrogens in mice. In serum-free medium, bisphenol A, a component of polycarbonates and of resins used to line metal food cans, showed a lower relative binding affinity (RBA; 0.006/100) than octylphenol (0.072/100) and nonylphenol (0.026/100), which are used as surfactants in many commercial products (all RBAs are relative to estradiol, which is equal to 100/100).