title: Evidence for reduction of pro-atherosclerotic properties in platelets from healthy centenarians.
abstract: The aim of the present study was to investigate if aging is associated with platelet membrane modifications possibly related with cellular activation and hyperaggregability and if platelets from centenarians show different properties which might play a role in successful aging and longevity. Platelet plasma membranes were obtained from 60 healthy subjects, divided into four groups according to the age range: (1) 21-39 years; (2) 40-59 years; (3) 60-79 years; (4) centenarians (>/=100 years). Both centenarians and control subjects were submitted to the following inclusion criteria: liver, kidney, and thyroid function tests within the normal range; absence of history of diabetes, hypertension or coronary heart disease; no signs of edema or dehydration; no drug or vitamin supplement in the 4 weeks before the study; absence of Alzheimer's disease or secondary dementia. The following determinations were performed: lipid peroxide levels (Lp) evaluated by the measurement of thiobarbituric acid (TBA) reactivity, fluidity studied by the fluorescence anisotropy of the probe 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH), Na(+)/K(+)-ATPase activity measured by the method of Kitao and Hattori, and sialic acid (SA) content evaluated by the periodate-thiobarbituric acid method. Centenarians showed: (i) Lp concentrations lower than elderly subjects; (ii) increased Na(+)/K(+)-ATPase activity compared with adult and elderly subjects; (iii) higher TMA-DPH anisotropy than elderly subjects; (iv) SA content similar to the young and adult groups.The present work found deep platelet membrane modifications in centenarians compared with elderly subjects. These changes are likely associated with a decreased platelet activation and therefore might exert a protective role against cardiovascular accidents, as platelet activation is a key event in the initiation and progression of arteriosclerosis.
authors.affiliation: Department of Diabetology Research, Italian National Research Center on Aging, Ancona, Italy.
authors.forename: Rosa Anna
authors.initials: RA
authors.lastname: Rabini
authors.forename: Arianna
authors.initials: A
authors.lastname: Vignini
authors.forename: Daniela
authors.initials: D
authors.lastname: Martarelli
authors.forename: Laura
authors.initials: L
authors.lastname: Nanetti
authors.forename: Eleonora
authors.initials: E
authors.lastname: Salvolini
authors.forename: Maria Rosaria
authors.initials: MR
authors.lastname: Rizzo
authors.forename: Emilia
authors.initials: E
authors.lastname: Ragno
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Paolisso
authors.forename: Claudio
authors.initials: C
authors.lastname: Franceschi
authors.forename: Laura
authors.initials: L
authors.lastname: Mazzanti
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D001161:Arteriosclerosis / Q000097:blood; D001792:Blood Platelets / Q000502:physiology*; D006801:Humans; D007677:Kidney Function Tests; D008111:Liver Function Tests; D008560:Membrane Fluidity; D008875:Middle Aged; D019158:N-Acetylneuraminic Acid / Q000032:analysis; D010979:Platelet Function Tests; D000254:Sodium-Potassium-Exchanging ATPase / Q000032:analysis; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013960:Thyroid Function Tests
chemical_list: D017392:Thiobarbituric Acid Reactive Substances; D000254:Sodium-Potassium-Exchanging ATPase; D019158:N-Acetylneuraminic Acid