Adenine nucleotide metabolism in pigeon liver and heart: diurnal changes and correlations between indices

The adenine nucleotide and Pi content of pigeon liver and heart were determined, and the energy charge, phosphoryl potential and mass action ratio of adenylate kinase were calculated over the 24 hr period. All the indices of adenine nucleotide metabolism were shown to vary a 2- to 4-fold extent, both in liver and heart. The correlation coefficients for each of the adenine nucleotides and each of the calculated indices were computed and shown to be different for liver and heart. The difference between pigeon liver, pigeon heart and rat liver in the diurnal variation of adenine nucleotide metabolism, in the regulatory mechanism, and in metabolism on the whole is discussed.