7951
Inhibition by phenformin of oxygen consumption via complex I respiration in isolated rat liver mitochondria was greater than that in heart mitochondria , whereas inhibitory effect of phenformin on complex I respiration was similar in inside - out structured submitochondrial particles prepared from rat livers and hearts .
 phenformin, oxygen, phenformin
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 phenformin, oxygen, phenformin