28540
Ovx mice were replaced with vehicle ( sesame oil ) or 17 beta - estradiol ( E2 ) for 2 days or 30 min prior to a cocaine challenge to investigate the time course of E2 ' s effects .
 Chemical: 17 beta - estradiol; Chemical: cocaine
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: 17 beta - estradiol; Chemical: cocaine