~13C-NMR spectroscopic evaluation of the citric acid cycle flux in conditions of high aspartate transaminase activity in glucose-perfused rat hearts

摘要

A new mathematical model, based on the observation of ~13C-NMR spectra of two principal metabolites(glutamate and aspartate), was constructed to determine the citric acid cycle flux in the case of high aspartate transaminase activity leading to the formation of large amounts of labeled aspartate and glutamate. In this model, the labeling of glutamate and aspartate carbons by chemical and isotopic exchange with the citric acid cycle are considered to the interdependent. With [U-~13C] Glc or [1, 2- ~13C] acetate as a substrate, all glutamate and aspartate carbons can be labeled.