In vivo 13C NMR assessment of brain glycogen concentration and turnover in the awake rat

Neurochem Int. Sep-Oct 2003;43(4-5):317-22. doi: 10.1016/s0197-0186(03)00018-4.


Brain glycogen metabolism was recently observed in vivo and found to be very slow in the lightly alpha-chloralose anesthetized rat [J. Neurochem. 73 (1999) 1300]. Based on that slow turnover, the total glycogen content in the awake rat brain and its turnover time were assessed after administering 13C-labeled glucose for 48 h. Label incorporation into glycogen, glucose, amino acid, and N-acetyl-aspartate (NAA) resonances was observed. The amount of 13C label incorporated into glycogen was variable and did not correlate with that in glutamate (r=-0.1, P>0.86). However, the amount of 13C label incorporated into glycogen was very similar to that in NAA (r=0.93), implying similar turnover times between brain glycogen and NAA (approximately 10 h). Absolute quantification of the total concentration of brain glycogen in the awake, normoglycemic rat yielded 3.3+/-0.8 micromol/g (n=6, mean+/-S.D.).

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Brain / metabolism*
  • Carbon Isotopes
  • Glycogen / metabolism*
  • Magnetic Resonance Spectroscopy
  • Male
  • Rats
  • Rats, Sprague-Dawley
  • Wakefulness


  • Carbon Isotopes
  • Glycogen