1787
In the present study , we investigated the changes occurring at the protein level in striatal samples obtained from the unilaterally 6 - hydroxydopamine - lesion rat model of PD treated with saline , L - DOPA or bromocriptine using two - dimensional difference gel electrophoresis and mass spectrometry ( MS ) .
 6 - hydroxydopamine, PD, L - DOPA, bromocriptine
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 6 - hydroxydopamine, PD, L - DOPA, bromocriptine