Changes in probe sensitivity during nmr spectroscopic studies of the perfused rat heart: a warning

Abstract
During NMR experiments on isolated, perfused rat heart, we observed a 57% change in probe sensitivity when the perfusion buffer surrounding the heart was replaced by either a low‐ionic‐strength mannitol solution or air and the heart was made ischemic. Such changes in sensitivity, should they go unrecognized, would result in substantial quantification errors.