31P-NMR investigation of solid tumours in the living rat

Abstract
The 31P-NMR spectra of living tumors (Walker 256 carcinosarcomas) were obtained using surface coils and were unlike those of normal tissues. Contrary to expectations, their intracellular pH (measured from the chemical shift of the pi peak) was only slightly more acid than that of normal rat muscle, and glucose infusion did not depress it. When deoxyglucose was infused, the tumor intracellular pH measured from the chemical shift of the deoxyglucose-6-phosphate peak was much lower (6.44 .+-. 0.02) than that measured from the phosphate peak (7.14 .+-. 0.01).