24437
Neither alpha - elapitoxin - Ppr1 ( 0 . 1 mu M ) nor alpha - elapitoxin - Pc1 ( 0 . 1 mu M ) had a significant effect on the electrically - induced twitches of the rat isolated phrenic nerve - diaphragm preparation .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 None