20287
They were further pharmacologically characterized by competition using ( 125 ) I - KTX bound to its specific binding sites on rat brain synaptosomes .
 Chemical: ( 125 ) I
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: ( 125 ) I