4303
Opioid receptor binding affinity and activity were assessed using [ ( 3 ) H ] - diprenorphine binding , guanosine - 5 ' - O - ( 3 - [ 35S ] - thio ) triphosphate ( [ ( 35 ) S ] - GTP gamma S ) binding and isolated guinea - pig ileum .
 [ ( 3 ) H ] - diprenorphine, guanosine - 5 ' - O - ( 3 - [ 35S ] - thio ) triphosphate, [ ( 35 ) S ] - GTP gamma S
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 [ ( 3 ) H ] - diprenorphine, guanosine - 5 ' - O - ( 3 - [ 35S ] - thio ) triphosphate, [ ( 35 ) S ] - GTP gamma S