title: Detection of membrane fluidity in submitochondrial particles of platelets and erythrocyte membranes from Mexican patients with Alzheimer disease by intramolecular excimer formation of 1,3 dipyrenylpropane.
abstract: It has been suggested that mitochondrial dysfunction and defects in membrane structure could be implied in AD pathogenesis. The aim of the present work was the study of membrane fluidity in submitochondrial platelet particles and erythrocyte membranes from Mexican patients. Blood samples were obtained from 30 patients with Alzheimer disease and 30 aged-matched control subjects. Membrane fluidity determinations were done using a very low concentration of the fluorescent dipyrenylpropane probe incorporated in both types of membranes. This probe is able to give excimer and monomer fluorescence, therefore it can be used to monitor fluidity changes in biological membranes. The data obtained showed that in submitochondrial particles from AD patients, the excimer to monomer fluorescent intensity ratio was lower (0.231 +/- 0.008) than aged-matched control subjects (0.363 +/- 0.014). Therefore, membrane fluidity was lower in AD samples. On the other hand, we found similar membrane fluidity in erythrocytes from AD patients and aged-matched controls: the fluorescent intensity ratios were 0.312 +/- 0.03 and 0.305 +/- 0.033, respectively. In addition, lipid peroxidation in submitochondrial particles and erythrocyte membranes was higher in AD samples than in aged-matched controls. These data suggest that submitochondrial platelet particles are more sensitive to oxidative stress than erythrocyte membranes.
authors.affiliation: Enfermedades Neurodegenerativas, Division Neurociencias, Centro de Investigación Biomédica de Occidente (CIBO), Instituto Mexicano de Seguro Social (IMSS), Guadalajara, Jalisco, México. genarogabriel@yahoo.com
authors.forename: G G
authors.initials: GG
authors.lastname: Ortiz
authors.forename: F
authors.initials: F
authors.lastname: Pacheco-Moisés
authors.forename: M
authors.initials: M
authors.lastname: El Hafidi
authors.forename: A
authors.initials: A
authors.lastname: Jiménez-Delgado
authors.forename: M A
authors.initials: MA
authors.lastname: Macías-Islas
authors.forename: S A
authors.initials: SA
authors.lastname: Rosales Corral
authors.forename: A Célis
authors.initials: AC
authors.lastname: de la Rosa
authors.forename: V J
authors.initials: VJ
authors.lastname: Sánchez-González
authors.forename: E D
authors.initials: ED
authors.lastname: Arias-Merino
authors.forename: I E
authors.initials: IE
authors.lastname: Velázquez-Brizuela
mesh_terms: D000544:Alzheimer Disease / Q000097:blood*; D001792:Blood Platelets / Q000648:ultrastructure*; D004910:Erythrocyte Membrane / Q000648:ultrastructure*; D006801:Humans; D015227:Lipid Peroxidation; D008560:Membrane Fluidity; D008800:Mexico; D011721:Pyrenes / Q000378:metabolism*; D013367:Submitochondrial Particles
chemical_list: D011721:Pyrenes; C035116:1,3-di-(1-pyrenyl)propane