14209
The data suggest that the decrease in tissue levels of 5 - HT produced by MDMA is accompanied by a decrease in tryptophan hydroxylase activity but cannot be explained by supersensitivity of the 5 - HT1a autoreceptor .
 Chemical: 5 - HT; Chemical: MDMA; Chemical: tryptophan
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: 5 - HT; Chemical: MDMA; Chemical: tryptophan