title: Thermal properties and fluidity of human erythrocyte membranes in diabetes mellitus.
abstract: Exposure of human erythrocytes to elevated temperatures induces a decrease in stability of the cell membrane. Thermally induced haemolysis of erythrocytes from patients with type 1 diabetes and from healthy control individuals was measured as a function of duration of exposure to heat between 48.0 and 54.0 degrees C. Results indicate that the thermosensitivity of erythrocytes from patients with type 1 diabetes is lower than for control individuals. Activation energies for lysis were similar for both control and 'diabetic' erythrocytes, being 298.3 and 287.7 kJ/mol, respectively. The steady-state fluorescence anisotropy measurement of TMA-DPH for each step of haemolysis was employed as a parameter characterizing membrane fluidity. We found that 'diabetic' erythrocyte membranes had significantly decreased fluidity. The relationship between fluidity and rate of haemolysis indicates that the rate-limiting step in the haemolysis reaction involves the rupturing of the membrane bilayer.
authors.affiliation: Department of Biophysics, University of Lodz, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Przybylska
authors.forename: M
authors.initials: M
authors.lastname: Bryszewska
authors.forename: I V
authors.initials: IV
authors.lastname: Chapman
mesh_terms: D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D004161:Diphenylhexatriene / Q000031:analogs & derivatives; D004910:Erythrocyte Membrane / Q000502:physiology*; D005456:Fluorescent Dyes; D006461:Hemolysis / Q000502:physiology; D006358:Hot Temperature; D006801:Humans; D066298:In Vitro Techniques; D008560:Membrane Fluidity / Q000502:physiology*
chemical_list: D005456:Fluorescent Dyes; D004161:Diphenylhexatriene; C033628:1-(4-(trimethylamino)phenyl)-6-phenylhexa-1,3,5-triene