5408
Selective competitive antagonists of Gi - coupled endothelin - 1 type A and B receptors were ~ 60 % effective in blocking As ( III ) inhibition and combination of antagonists to both receptors were 85 % effective .
 As ( III )
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 As ( III )