Metabolic Studies using Localized Magnetic Resonance Spectroscopy

Abstract

Nuclear magnetic resonance (NMR) spectroscopy provides a non-invasive method of studying metabolism in vivo. The nucleus that has been most widely used for metabolic studies is 31P, which is 100% naturally abundant. 31P spectra include signals from ATP, phosphocreatine (PCr) (in brain and muscle), and inorganic phosphate (Pi), and in addition to measuring the relative concentrations of these metabolites, it is also possible to determine the intracellular pH. In view of the key role of PCr, ATP and Pi in energy metabolism, together with the intracellular pH changes that may be associated with lactic acid production, 31P NMR can be used to study the metabolic changes that occur in response to large decreases in energy supply or increases in energy demand, as in ischaemic disease or muscular exercise (Radda et al. 1984; Radda, 1986). The ability to distinguish different energy states is also valuable in monitoring cancer metabolism and response to therapy (Evanochko et al. 1984)