Dose Response Uterine Wet Weights (UWW). UWW was measured across several EE and TAM doses in the mouse and rat. A plot of the fold change increase in wet weight is plotted. A dose response curve was fit to the data (GraphPad 4.0) to estimate EC50 values. 100 μg/kg b.w. approximates the maximum response in all four cases and was used in subsequent time course studies. ED50 values were comparable between ligands in the rat while exhibiting only a two fold difference in the mouse, indicating conservation of sensitivity to EE and TAM.