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Brain levels of 5 - HT and its metabolite , 5 - hydroxyindoleacetic acid ( 5 - HIAA ) , were determined using HPLC .
 Chemical: 5 - HT; Chemical: 5 - hydroxyindoleacetic acid; Chemical: 5 - HIAA
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: 5 - HT; Chemical: 5 - hydroxyindoleacetic acid; Chemical: 5 - HIAA