Premium
A 31 P NMR study of the GI tract: Effect of fructose loading and measurement of transverse relaxation times
Author(s) -
Karczmar G. S.,
Tavares N. J.,
Weiner M. W.
Publication year - 1989
Publication title -
magnetic resonance in medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.696
H-Index - 225
eISSN - 1522-2594
pISSN - 0740-3194
DOI - 10.1002/mrm.1910090103
Subject(s) - jejunum , fructokinase , fructose , ileum , chemistry , nuclear magnetic resonance , nuclear magnetic resonance spectroscopy , relaxation (psychology) , small intestine , biochemistry , medicine , physics , stereochemistry
The effect of fructose loading on high‐energy phosphates in the jejunum, ileum, and large intestine of rats was studied using 31 P NMR. Following fructose loading, an increase in the intensity of the PME resonance was observed in the jejunum, indicating an accumulation of fructose‐1‐phosphate. There were no significant changes in ATP or P i . This demonstrates that the activity of fructokinase in the jejunum can be monitored by 31 P NMR. Fructose loading had no detectable effect on metabolite levels in the ileum and large intestine. Resolution of intestinal spectra was poor due to unusually large linewidths and the presence of broad underlying signals. To study the mechanism of line broadening, the T 2 's of the phosphorus resonances were measured using a solenoidal coil. The T 2 's ofthe ATP or P i , PME. and PCr resonances were much longer than the T 2 's, suggesting that the linewidths of these resonances are primarily due to susceptibility gradients and/or compartmentation of metabolites. Other signals, particularly in the PDE region, were homogeneously broadened and had very short T 2 's. Spin echoes obtained with evolution times of 1 to 4 ms suppressed these broad components, with little loss of intensity in the inhomogeneously broadened resonances; as a result, resolution was improved. © 1989 Academic Press, Inc.