Measurement of changes in high-energy phosphates in the cardiac cycle using gated 31P nuclear magnetic renonance.

Abstract

Levels of the high-energy phosphate containing compounds, ATP and creatine phosphate, and Pi were measured as a function of position in the cardiac cycle. Measurements were made on isolated, perfused, working rat hearts through the use of gated 31P NMR spectroscopy. Levels of ATP and creatine phosphate varied during the cardiac cycle and were maximal at minimal aortic pressure and minimal at maximal aortic pressure. Pi varied inversely with the high-energy phosphates.