Nuclear magnetic resonance spin-lattice times of normal and transformed cultured mammalian cells and of normal and neoplastic animal tissues.

Proton spin-lattice relaxation times (T1) for normal tissues and cultured cells, and for neoplastic tissues and transformed culture cells, were measured. Increases in T1 of neoplastic tissue and normal tissues of mice with neoplasms were observed. No difference was found between T1 of normal 3T3 cells and of an SV40 viral transformed cell line. These data imply that changes in T1 of neoplastic tissue may not be due to intrinsic properties of cancerous cells but rather to physiological interaction of the neoplasm with its physiological environment. The measurement of several tissues of rat showed a good correlation between T1 and tissue water content, and addition of water by glass capillary increased T1 of samples. For samples in sealed NMR tubes, however, changes in T1 were incurred by boiling, freezing, or storage at various temperatures. These data imply that changes in T1 may be influenced by cellular water content as well as macromolecular conformation.