2461
At a low pH ( pH 7 . 4 ) , but not pH 7 . 9 , ifenprodil reduces the mean open time of GluN1 / GluN2B receptors , which may be responsible for its usefulness as a context - dependent inhibitor in conditions like ischemia and stroke , when the pH of the extracellular milieu becomes acidic .
 ifenprodil
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 ifenprodil