4110
In vitro perfusion of bepridil in the life - support medium for isolated sino - atrial tissue from rabbit heart , caused a reduction in action potential ( AP ) spike frequency ( recorded by KCl microelectrodes ) starting at doses of 5 X 10 ( - 6 ) M .
 Chemical: bepridil; Chemical: KCl
Please list all entity words in the text that fit the category.Output format is "type1: word1; type2: word2". 
Option: Disease, Chemical 
Text: {0} 
Answer:
 Chemical: bepridil; Chemical: KCl