87Rb NMR studies of the perfused rat heart

Abstract
We have studied 87Rb+ fluxes in the perfused rat heart using nuclear magnetic resonance spectroscopy (NMR). A simple model for the interpretation of the data is presented. A comparison of radioactively measured K+ fluxes and the K+ fluxes deduced from the 87Rb+ measurements shows them to be very similar. This method provides a means of noninvasively measuring uni-directional K+ fluxes in the heart.