Cerebral metabolism in brain tumor of mice studied by in vivo 31P-NMR spectroscopy

Summary We now report a mouse model system of brain tumor for 31 P-NMR spectroscopic study of in vivo cerebral metabolism. In vivo 31 P-NMR (109 MHz) spectra were taken on the 9th day by the Faraday shield method of the brain of mice (3-week-old) transplanted intracerebrally with mKS·A tumor cells. In tumorbearing mice, the amount of creatine phosphate decreased markedly and that of inorganic phosphate plus sugar phosphate increased accordingly. Furthermore, the broadening and splitting of individual signals were also noted with tumorbearing mice; this is interpreted as indicating a variety of changes in chemical shift occurring in the brain of the animals due to heterogeneous distribution of pH. Binding or detaching of divalent cations to and from phosphometabolites may also be responsible for these changes.