Glycogen metabolism: a 13C‐NMR study on the isolated perfused rat heart

Abstract
Glycogen synthesis from D‐[1‐13C]glucose was observed in the perfused rat heart by 13C‐NMR spectroscopy at 62.9 MHz. The glycogenogenesis was stimulated by pretreatment of the animals with isoprenaline. Whereas in hearts from control rats the incorporation of D‐[1‐13C]glucose into the glycogen remained below the detection threshold, 5 min proton‐decoupled 13C‐NMR spectra revealed, in hearts from treated rats, a significant labelling of the glycogen within the first minutes of the perfusion and a further linear increase of the glycogen resonance for up to 25 min. This model was used to monitor the appearance of 13C‐labelled lactate during ischemia.