20366
Although the local administration of morphine ( 50 - 200 mu g ) was devoid of antinociceptive effects in WT mice , it induced dose - dependent antinociception in sigma 1 - KO mice .
 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