In vivo 1H- and 31P-MR spectroscopy of the fatty liver in monosodium glutamate-treated rats

The livers of monosodium glutamate (MSG)-treated rats and normal control rats were investigated in vivo using 1H- and 31P-magnetic resonance (MR) spectroscopy. The liver of MSG-treated rats showed a remarkable fatty change histologically and their triglyceride content was much greater than that in control rats. 1H-MR spectra of MSG-treated rats showed an obvious fat peak in addition to a water peak. There was an excellent correlation between the peak area ratio of fat to fat plus water obtained from 1H-MR spectroscopy in vivo and triglyceride content in the liver specimens measured by a thinlayer-chromatography-flame-ionization (TLC-FID) metbod. 31P-MR spectra of both MSG-treated and control rats revealed 6 peaks, which were assigned to phosphomonoester (PME), inorganic phosphate (Pi), phosphodiester (PDE), γ-ATP, α-ATP, β-ATP. The peak height ratio of Pi to α-ATP was higher in MSG-treated rats than in control rats. The chemical shift of Pi relative to α-ATP was smaller in MSG-treated rats than in control rats, suggesting a slight acidosis in the liver of MSG-treated rats. These data demonstrated that 1H- and 31P-MR spectroscopy were useful for evaluation of accumulation of fat and related metabolic derangements in fatty liver.