Water content and spin lattice relaxation times of cultured mammalian cells subjected to various salt, sucrose, or DMSO solutions.

The proton spin lattice relaxation time (T1) of mammalian cells subjected to a wide range of salt, sucrose, or DMSO solutions has been measured and minima in the T1 curves for cells treated with all solutes except DMSO were observed. At hypotonic solute concentrations, the increases observed in T1 of the cell sample could be correlated to an increase in the amount of intracellular water. At high solute concentrations, cells shrink losing intracellular water; yet increases in T1 were observed. The increases were attributed to changes in macromolecular conformation resulting in changes in the coordination shells associated with the macromolecules. Since these effects are also observed with sucrose, the basic phenomenon is concluded to be due to osmotic factors. However, ion specific effects were also observed. When protein was dissolved in a wide range of NaCl or KCl solutions, the minimum in the T1 curve was not observed, demonstrating that the effect must be characteristic of the response of intact cells to the various solutions.