23075
PQ did not alter the concentration of dopamine ( DA ) , homovanillic acid ( HVA ) or 3 , 4 - dihydroxyphenylacetic acid ( DOPAC ) , or increase dopamine turnover in the striatum .
 dopamine, homovanillic acid, HVA, 3 , 4 - dihydroxyphenylacetic acid, DOPAC, dopamine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 dopamine, homovanillic acid, HVA, 3 , 4 - dihydroxyphenylacetic acid, DOPAC, dopamine