13809
In the present study , we show that ( + ) - naloxone can potentiate DAMGO - induced feeding at doses at which ( - ) - naloxone was an antagonist .
 Chemical: ( + ) - naloxone; Chemical: DAMGO; Chemical: ( - ) - naloxone
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: ( + ) - naloxone; Chemical: DAMGO; Chemical: ( - ) - naloxone