title: 31P MAS-NMR of human erythrocytes: independence of cell volume from angular velocity.
abstract: 31P 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.
authors.affiliation: School of Molecular and Microbial Biosciences, University of Sydney, NSW, Australia. p.kuchel@mmb.usyd.edu.au
authors.forename: P W
authors.initials: PW
authors.lastname: Kuchel
authors.forename: W A
authors.initials: WA
authors.lastname: Bubb
authors.forename: S
authors.initials: S
authors.lastname: Ramadan
authors.forename: B E
authors.initials: BE
authors.lastname: Chapman
authors.forename: D J
authors.initials: DJ
authors.lastname: Philp
authors.forename: M
authors.initials: M
authors.lastname: Coen
authors.forename: J E
authors.initials: JE
authors.lastname: Gready
authors.forename: P J
authors.initials: PJ
authors.lastname: Harvey
authors.forename: A J
authors.initials: AJ
authors.lastname: McLean
authors.forename: J
authors.initials: J
authors.lastname: Hook
mesh_terms: D003198:Computer Simulation; D004911:Erythrocyte Volume; D006801:Humans; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D009943:Organophosphorus Compounds; D010761:Phosphorus Radioisotopes; D011312:Pressure; D013696:Temperature
chemical_list: D009943:Organophosphorus Compounds; D010761:Phosphorus Radioisotopes; C031116:dimethyl methylphosphonate