27506
Conversely , ovarian PRA and PRB were positively regulated by ethanol and ethanol - melatonin combination , whereas PRA was down - regulated in the uterus and oviduct after ethanol consumption .
 ethanol, ethanol, melatonin, ethanol
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 ethanol, ethanol, melatonin, ethanol