28541
To examine receptor mediation of estradiol effects , Ovx mice replaced for 2 days with either the ER alpha - selective agonist PPT or the ER beta - selective agonist DPN were compared to Sham mice , and mice lacking either ER alpha ( alpha ERKO ) or ER beta ( beta ERKO ) were compared to WT littermates .
 Chemical: estradiol; Chemical: PPT; Chemical: DPN
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Chemical 
Text: {0} 
Answer:
 Chemical: estradiol; Chemical: PPT; Chemical: DPN