A spectrophotometric method for the determination of creative phosphokinase and myokinase

Abstract

A rapid spectrophotometric method was developed for the assay of creatine phosphokinase and myokinase in tissue extracts and homogenates. The formation of adenosine triphosphate by these enzymes is coupled to the reduction of triphosphopyridine nucleotide and the rate of reduction gives a measure of the activities. The sensitivity of the method enables the determination of enzymic activities in tissue preparations diluted as much as one part in 20,000 corresponding to a quantity of tissues of about 300 [mu]g wet weight. Under these conditions reactions due to endogenous substances are negligible. The method was applied to the measurement of creatine phosphokinase and myokinase in various tissues of the rat.