Selective, in Vivo Observation of (5-15N)Glutamine Amide Protons in Rat Brain by 1H-15N Heteronuclear Multiple-Quantum-Coherence Transfer NMR

✍ Scribed by K. Kanamori; B.D. Ross; J. Tropp

• Publisher: Elsevier Science
• Year: 1995
• Tongue: English
• Weight: 682 KB
• Volume: 107
• Category: Article
• ISSN: 1064-1866
• DOI: 10.1006/jmrb.1995.1066

✦ Synopsis

The amide protons of [5-15N]glutamine were selectively observed in vivo in the brains of anesthetized, spontaneously breathing rats after intravenous 15NH4+ infusion by 1H-15N heteronuclear multiple-quantum-coherence (HMQC) transfer NMR at 200 MHz for 1H. The peak intensity of the upfield amide proton was proportional to brain [5-15N]glutamine concentration. The 15N-decoupled amide-proton signal was observed in vivo in 2 min of acquisition at a brain [5-15N]glutamine concentration of 7.7 +/- 0.4 mumol/g, in < 8 min at 4.35 +/- 0.15 mumol/g, and in 17-34 min at 2.0 +/- 0.1 mumol/g. 1H signals not coupled to 15N were suppressed by phase cycling. The result suggests that 1H-15N HMQC will be useful for kinetic study of glutamine synthesis in rat brain in vivo at physiological concentrations of brain ammonia.