Title | Determination of absolute phosphate metabolite concentrations in RIF-1 tumors in vivo by 31P-1H-2H NMR spectroscopy using water as an internal intensity reference. |
Publication Type | Journal Article |
Year of Publication | 1992 |
Authors | Shungu DC, Bhujwalla ZM, Li SJ, Rose LM, Wehrle JP, Glickson JD |
Journal | Magn Reson Med |
Volume | 28 |
Issue | 1 |
Pagination | 105-21 |
Date Published | 1992 Nov |
ISSN | 0740-3194 |
Keywords | Animals, Body Water, Chromatography, High Pressure Liquid, Fibrosarcoma, Fluorouracil, Magnetic Resonance Spectroscopy, Mice, Mice, Inbred C3H, Neoplasm Transplantation, Neoplasms, Radiation-Induced, Phosphates |
Abstract | The absolute metabolite quantification method of Thulborn and Ackerman [J. Magn. Reson. 55, 357 (1983)] in which the tissue water proton signal is used as an internal intensity standard and its more recent variation in which NMR peak intensities are referenced to that of the natural abundance deuterium signal of water [Li et al., SMRM Abstr. 2, 825 (1988); Song et al., Magn. Reson. Med. 25, 45 (1992) have been implemented to obtain absolute phosphate metabolite concentrations in subcutaneous RIF-1 tumors during untreated growth and following treatment with 5-fluorouracil. The equivalence of these two hydrogen isotopes as intensity standards and the validity of their use in the determination of absolute metabolite concentrations in vivo by NMR has been demonstrated. On matched in vivo and extract tumor samples (n = 5), excellent agreement has been obtained between nucleoside triphosphate concentrations determined by NMR and those derived by HPLC analysis for the control tumors. Following 3 days of untreated growth, absolute concentrations of phosphate metabolites in RIF-1 tumors (n = 10) decreased significantly, except for the Pi concentration which did not vary. For the treated tumors (n = 10) there were no changes in metabolite concentrations except for a decrease in the PCr and, possibly, Pi concentrations. The PCr/Pi ratio in the latter tumors did not change. These observations suggest that changes in absolute metabolite concentrations may be more sensitive indices of response to therapy than changes in metabolite peak amplitude ratios, a parameter commonly used to express in vivo NMR data. |
DOI | 10.1002/mrm.1910280111 |
Alternate Journal | Magn Reson Med |
PubMed ID | 1435214 |
Grant List | CA44703 / CA / NCI NIH HHS / United States CA51950 / CA / NCI NIH HHS / United States |
Related Institute:
MRI Research Institute (MRIRI)