Kuchel, Philip WilliamBubb, William ARamadan, SChapman, B EPhilp, D JCoen, MGready, JillHarvey, PetaMcLean, Allan JHook, J2015-12-130740-3194http://hdl.handle.net/1885/8635331P magic angle spinning NMR (MAS-NMR) spectra were obtained from suspensions of human red blood cells (RBCs) that contained the cell-volume-sensitive probe molecule, dimethyl methylphosphonate (DMMP). A mathematical representation of the spectral-peak shape, including the separation and width-at-half-height in the 31P NMR spectra, as a function of rotor speed, enabled us to explore the extent to which a change in cell volume would be reflected in the spectra if it occurred. We concluded that a fractional volume change in excess of 3% would have been detected by our experiments. Thus, the experiments indicated that the mean cell volume did not change by this amount even at the highest spinning rate of 7 kHz. The mean cell volume and intracellular 31P line-width were independent of the packing density of the cells and of the initial cell volume. The relationship of these conclusions to other non-NMR studies of pressure effects on cells is noted.Keywords: methylphosphonic acid dimethyl ester; phosphonic acid derivative; phosphorus 31; unclassified drug; diagnostic agent; methylphosphonic acid dimethyl ester; organophosphorus compound; phosphorus; article; cell density; cell level; cell volume; erythrocyte; 31P MAS-NMR; Dimethyl methylphosphonate; Magic angle spinning; Red blood cells200410.1002/mrm.201392015-12-12