The determination of oxidized and reduced diphosphopyridine nucleotide and triphosphopyridine nucleotide in animal tissues

Abstract

Sensitive methods have been devised for the separate determination of both oxidized and reduced coenzymes in neutralized acid and alkaline tissue extracts respectively, oxidized coenzymes being relatively stable in dilute acid, whereas reduced coenzymes are relatively stable in dilute alkali (see Reduced diphospho- pyridine nucleotide (DPN) and triphosphopyridine nucleotide (TPN), continuously formed in the presence of ethanol and alcohol dehydrogenase or glucose 6-phosphate (G 6-P) and G 6-P dehydro- genase respectively, are coupled with their re- spective cytochrome c reductases and the rate of reduction of cytochrome c is followed spectro- photometrically.