The behaviour of pyridine nucleotides of mitochondria in a ‘saline medium’

The considerable volume of information obtained about the metabolism of the endogenous pyridine nucleotides of mitochondria has been derived from experiments in many different fields of research. Rarely have the investigations been con- cemed primarily with the reactions of the indi- vidual nucleotides themselves, though the work of Chance and his collaborators has thrown much light on the general pattem of behaviour of the mitochondrial coenzymes (for references to the need for investigations supplementary to this work see Chance & Baltscheffsky, 1958). Indeed, no syste- matic study of the reactions of the endogenous oxidized and reduced diphosphopyridine nucleotides and the oxidized and reduced triphosphopyridine nucleotides of mitochondria isolated by a standard procedure and subsequently incubated under a variety of experimental conditions has been reported. This paper describes an investigation of the reactivity of the pyridine nucleotides of mitochondria suspended in a 'saline medium' and the influence of the components of this medium on the behaviour of the coenzymes. MATERIALS 5-Ethyl-5-isoamylbarbiturate (amytal). This was obtained from Eli Lilly and Co. Ltd., Basingstoke, and freshly prepared solutions of the sodium salt were used in each experiment.