18709
Changes in vitellogenin ( VTG ) concentration , liver 7 - ethoxyresorufin - O - deethylase ( EROD ) activity and circulating serum E2 level were examined .
 7 - ethoxyresorufin, O, E2
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 7 - ethoxyresorufin, O, E2