title: Influence of the spinning rate in the HR-MAS pattern of mobile lipids in C6 glioma cells and in artificial oil bodies.
abstract: OBJECTIVE
  To evaluate how spinning rate affects mobile lipid (ML) resonances visibility in HR-MAS spectra of C6 glioma cells and artificial oil bodies (AOB), as models of cytosolic lipid droplets.
  
  
  METHODS
  Using C6 cells and AOB of two different sizes, 780 ± 580 and 240 ± 293 nm, as models, we acquired HR-MAS pulse and acquire spectra at different spinning rates between 500 and 15,000 Hz, all at 37 °C.
  
  
  RESULTS
  Sample spinning at 15,000 Hz increased by 2.3 and 4.6-fold with respect to 500 Hz spinning the area of resonances corresponding to ML at 0.88 and 1.28 ppm, respectively, for log phase C6 cells. Furthermore, postconfluent C6 cells displayed an increase of 2.5-fold at 0.88 ppm and 4.2-fold at 1.28 ppm. These changes were reversible upon low speed spinning. AOBs did show much lower ML area increases (1.4-1.5-fold) upon high-speed HR-MAS.
  
  
  CONCLUSIONS
  ML can be reversibly mobilized in C6 glioma cells by high-speed HR-MAS, partially unveiling the NMR "invisible" ML pool. A small part of the ML pool also shows reduced visibility in freely tumbling AOBs.
authors.affiliation: Dept de Bioquímica i Biología Molecular, Unitat de Biociències, Edifici Cs, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain. jmartin@gabrmn.uab.es
authors.forename: Juana
authors.initials: J
authors.lastname: Martín-Sitjar
authors.forename: Teresa
authors.initials: T
authors.lastname: Delgado-Goñi
authors.forename: Miquel E
authors.initials: ME
authors.lastname: Cabañas
authors.forename: Jason
authors.initials: J
authors.lastname: Tzen
authors.forename: Carles
authors.initials: C
authors.lastname: Arús
mesh_terms: D000818:Animals; D002135:Calcium-Binding Proteins / Q000737:chemistry; D045744:Cell Line, Tumor; D002470:Cell Survival; D003600:Cytosol / Q000378:metabolism; D005227:Fatty Acids / Q000737:chemistry; D005910:Glioma / Q000378:metabolism / Q000473:pathology*; D008055:Lipids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D009821:Oils / Q000737:chemistry; D010940:Plant Proteins / Q000737:chemistry; D051381:Rats; D013696:Temperature
chemical_list: D002135:Calcium-Binding Proteins; D005227:Fatty Acids; D008055:Lipids; D009821:Oils; D010940:Plant Proteins; C402836:caleosin protein, Sesamum indicum; C110161:oleosin protein, Sesamum indicum