20372
These results show that sigma 1 receptor inhibition potentiates morphine - induced mechanical analgesia but not its acute side effects , and that this enhanced analgesia can be induced at peripheral level .
 Chemical: morphine
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