21320
RESULTS : While nitric oxide , synthetized by NOS1 and / or NOS2 , increased the local antinociceptive effects of morphine during acute and chronic pain , it decreased the inhibitory effects of morphine after visceral pain .
 Chemical: nitric oxide; Chemical: morphine; 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: nitric oxide; Chemical: morphine; Chemical: morphine