Tolbutamide, one of the hypoglycemic sulphonylurea drugs was fcund to decrease the respiratory control index of beef heart mitochondria as well as that of rat liver mitochondria. The effect of the drug on beef heart mitochondria was more pronounced than on liver mitochondria in the r an ge of concentrations of 30-80 mg% . It was of interest to find that DNP release of mitochondrial respiration ...
