20365
Similarly , systemic treatment of WT mice with sigma 1 antagonists markedly potentiated morphine - induced antinociception , and its effects were reversed by the selective sigma 1 agonist PRE - 084 .
 Chemical: morphine; Chemical: PRE - 084
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: morphine; Chemical: PRE - 084