title: Interactions between lipoproteins and platelet membranes in obesity.
abstract: The aim was to investigate low-density lipoprotein (LDL) composition and Na(+)/K(+) adenosine triphosphatase (ATPase) and Ca(2+) ATPase activities and membrane fluidity measured by 1-(4-trimethylaminophenyl)-6-phenyl-1,3,5-hexatriene (TMA-DPH) in platelets from obese patients and controls in order to identify, if any, platelet membrane's chemical-physical and/or functional modifications associated with compositional modification of circulating lipoproteins. Moreover, we studied the in vitro effect on both platelet transmembrane cationic transport and fluidity, by incubating LDL from 30 obese subjects with platelets from 30 control subjects. The analysis of the chemical composition of LDL from obese patients showed a significant increase in the percent content of total cholesterol (TC) and triglycerides (TGs) and in the mean levels of lipid hydroperoxides compared to controls' LDL. Platelet Na(+)/K(+) ATPase and Ca(2+) ATPase activities showed, respectively, a significant decrease and increase in patients compared to controls; minor significant, respectively, decreases and increases are shown also in control platelets incubated with LDL from obese patients. Anisotropy tested with TMA-DPH probe was significantly increased both in platelets from obese patients and in control platelets incubated with LDL from obese patients compared to control platelets. This study highlights that obesity induces remarkable modifications both in lipoproteins and platelets. Both platelet hyperfunction and quantitative/qualitative alterations in plasma lipoproteins, as well as an altered interaction between circulating lipoproteins and platelets, might play a relevant role in the increased prevalence of the early atherosclerotic lesions development in obese subjects. The present data point out that obesity might represent a major potentially modifiable risk factor for the onset of numerous complications, in particular cardiovascular ones.
authors.affiliation: Department of Biochemistry, Biology and Genetics, School of Medicine, Marche Polytechnic University, Ancona, Italy. raffi.3@virgilio.it
authors.forename: Francesca
authors.initials: F
authors.lastname: Raffaelli
authors.forename: Laura
authors.initials: L
authors.lastname: Nanetti
authors.forename: Monica
authors.initials: M
authors.lastname: D'Angelo
authors.forename: Giorgio
authors.initials: G
authors.lastname: Montecchiani
authors.forename: Alessandro
authors.initials: A
authors.lastname: Alidori
authors.forename: Luca
authors.initials: L
authors.lastname: Montesi
authors.forename: Emanuela
authors.initials: E
authors.lastname: Faloia
authors.forename: Arianna
authors.initials: A
authors.lastname: Vignini
authors.forename: Laura
authors.initials: L
authors.lastname: Mazzanti
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000166:cytology / Q000378:metabolism*; D000252:Calcium-Transporting ATPases / Q000378:metabolism; D016022:Case-Control Studies; D002462:Cell Membrane / Q000378:metabolism*; D002784:Cholesterol / Q000378:metabolism; D005260:Female; D006801:Humans; D008074:Lipoproteins / Q000378:metabolism*; D008077:Lipoproteins, LDL / Q000378:metabolism; D008297:Male; D008560:Membrane Fluidity / Q000502:physiology; D009765:Obesity / Q000378:metabolism*; D000254:Sodium-Potassium-Exchanging ATPase / Q000378:metabolism; D014280:Triglycerides / Q000378:metabolism
chemical_list: D008074:Lipoproteins; D008077:Lipoproteins, LDL; D014280:Triglycerides; D002784:Cholesterol; D000252:Calcium-Transporting ATPases; D000254:Sodium-Potassium-Exchanging ATPase