title: Effects of dietary fish oil supplementation on platelet aggregability and platelet membrane fluidity in normolipemic subjects with and without high plasma Lp(a) concentrations.
abstract: The purpose of this study was to compare the relative effect of n-3 fatty acids on plasma lipids and platelet function in normolipemic subjects (n = 8) with plasma Lp(a) levels greater than 30 mg/dl and normolipemic subjects (n = 7) without detectable plasma Lp(a) concentrations. Six weeks of dietary supplementation (3.8 g EPA and 2.9 g DHA/d) significantly reduced (P less than 0.005) plasma TGs in both groups whereas no changes of plasma TC, LDL-C, HDL-C, and Lp(a), respectively, were found. Collagen- or thrombin-stimulated platelet aggregation and collagen- or thrombin-induced TXB2 generation from platelets decreased by approx. 45% in Lp(a)-negative and Lp(a)-positive platelet donors after a 6 week dietary intake. Four more weeks without n-3 supplementation restored the pretreatment values of TGs, platelet aggregability and TXB2 release. The biophysical properties of platelets from normolipemics with and without high plasma Lp(a) concentrations revealed a similar structural order of platelets at 37 degrees C using DPH, TMA-DPH, or 6-AS as fluorescent probes. Also similar temperature-dependent changes in platelet fluidity from 37 degrees C to 17 degrees C were observed in platelet preparations from Lp(a)-positive and Lp(a)-negative subjects. However, no subtle changes in the structural order of platelets due to nutrient intakes were found in all subjects (n = 15, 19-28 yrs) using fluorescence polarization technique. The present data suggest a similar in vitro platelet behaviour from normolipemic subjects with and without high plasma levels of Lp(a) (which is considered a risk for premature atherosclerosis) in contrast to platelet aggregability and platelet fluidity in certain hyperlipidemic stages.
authors.affiliation: Institute of Medical Biochemistry, Karl-Franzens University, Graz, Austria.
authors.forename: E
authors.initials: E
authors.lastname: Malle
authors.forename: W
authors.initials: W
authors.lastname: Sattler
authors.forename: E
authors.initials: E
authors.lastname: Prenner
authors.forename: H J
authors.initials: HJ
authors.lastname: Leis
authors.forename: A
authors.initials: A
authors.lastname: Hermetter
authors.forename: A
authors.initials: A
authors.lastname: Gries
authors.forename: G M
authors.initials: GM
authors.lastname: Kostner
mesh_terms: D000328:Adult; D001792:Blood Platelets / Q000378:metabolism / Q000502:physiology*; D015525:Fatty Acids, Omega-3 / Q000494:pharmacology; D005395:Fish Oils / Q000494:pharmacology*; D005454:Fluorescence Polarization; D006801:Humans; D008055:Lipids / Q000097:blood*; D017270:Lipoprotein(a); D008074:Lipoproteins / Q000097:blood*; D008297:Male; D008560:Membrane Fluidity; D010974:Platelet Aggregation; D013929:Thromboxane B2 / Q000378:metabolism
chemical_list: D015525:Fatty Acids, Omega-3; D005395:Fish Oils; D008055:Lipids; D017270:Lipoprotein(a); D008074:Lipoproteins; D013929:Thromboxane B2