title: EPR spectroscopy studies of changes in erythrocyte membranes in patients with laryngeal cancer.
abstract: OBJECTIVE
  To evaluate microviscosity and sorption capacity of erythrocyte membranes (SCEM) from patients with laryngeal cancer (LC).
  
  
  METHODS
  Samples from 35 patients with LC of stages II and III and 20 healthy volunteers were investigated by electron paramagnetic resonance with Bis(1-oxyl-2,2,6,6-tetramethylpiperidinyl-4)-ester of 5,7-dimethyladamantane-1,3-dicarbonic acid (AdTEMPO) probe. SCEM was evaluated by amount of unabsorbed methylene blue.
  
  
  RESULTS
  Microviscosity of erythrocyte membranes was determined by the effective rotational diffusion correlation times (τeff) and a decrease in radical spectrum signal intensity per hour. The most apparent decrease in mobility of the AdTEMPO in erythrocytes was observed prior to washing of erythrocytes with 0.9% NaCl for 5 min after probe insertion. The deceleration after 60 min was observed only in stage II LC. τeff was at control values after washing of erythrocytes of stage II LC 5 min after probe insertion and was significantly reduced in stage III LC in comparison to control. Radical spectrum signal intensity per hour in samples of stage II and III patients prior to and after washing of erythrocytes was on average 1.5-fold higher than that of control. SCEM in samples of stage II and III LC was found in 40 and 33% cases, respectively and was on average significantly reduced in comparison to control.
  
  
  CONCLUSIONS
  The initial interaction of AdTEMPO with erythrocyte membranes of stage II and III LC patients is accompanied by an increase in τeff, indicating deceleration of probe rotation. τeff of the probe in membranes remains unchanged in 60 min, indicating changes in the structural organization of lipid bilayer and its associated proteins in particular. The similarity of SCEM for both studied groups reflects the pathological changes in function of erythrocyte membranes.
authors.affiliation: SE "Kolomiychenko Institute of Otolaryngology of the National Academy of Medical Sciences of Ukraine", Kyiv 03057, Ukraine.
authors.forename: Y B
authors.initials: YB
authors.lastname: Burlaka
authors.affiliation: SE "Institute of Bioorganic Chemistry and Petrochemistry of the National Academy of Sciences of Ukraine", Kyiv 03094, Ukraine.
authors.forename: O V
authors.initials: OV
authors.lastname: Sukhoveev
authors.affiliation: SE "Kolomiychenko Institute of Otolaryngology of the National Academy of Medical Sciences of Ukraine", Kyiv 03057, Ukraine.
authors.forename: N V
authors.initials: NV
authors.lastname: Grin
authors.affiliation: SE "Institute of Bioorganic Chemistry and Petrochemistry of the National Academy of Sciences of Ukraine", Kyiv 03094, Ukraine.
authors.forename: O M
authors.initials: OM
authors.lastname: Khilchevskyi
authors.affiliation: SE "Kolomiychenko Institute of Otolaryngology of the National Academy of Medical Sciences of Ukraine", Kyiv 03057, Ukraine.
authors.forename: S V
authors.initials: SV
authors.lastname: Verevka
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives / Q000737:chemistry; D000368:Aged; D002294:Carcinoma, Squamous Cell / Q000378:metabolism* / Q000473:pathology; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods*; D004910:Erythrocyte Membrane / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D007822:Laryngeal Neoplasms / Q000378:metabolism* / Q000473:pathology; D008051:Lipid Bilayers / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008560:Membrane Fluidity; D008563:Membrane Lipids / Q000737:chemistry / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000378:metabolism; D008875:Middle Aged; D015335:Molecular Probes / Q000737:chemistry; D015394:Molecular Structure; D009367:Neoplasm Staging; D010880:Piperidines / Q000737:chemistry; D013997:Time Factors; D014783:Viscosity
chemical_list: D008051:Lipid Bilayers; D008563:Membrane Lipids; D008565:Membrane Proteins; D015335:Molecular Probes; D010880:Piperidines; C000620885:bis(1-oxyl-2,2,6,6-tetramethylpiperidinyl-4)-ester of 5,7-dimethyladamantane-1,3-dicarbonic acid; D000218:Adamantane