Lipid fluidity modulates platelet aggregation and agglutination in vitro.
To determine the effect of altered membrane fluidity on platelet aggregation/agglutination, fresh, washed human platelets were treated with A2C, a cyclopropyl fatty acid ester which is known to enhance mobility of intrinsic membrane bilayer constituents and increase membrane fluidity. Fluorescence polarization studies demonstrated A2C incubation time- and concentration-dependent increases in platelet membrane fluidity (decreased fluorescence anisotropy). Preincubation with A2C was associated with diminished collagen, thrombin and ristocetin-induced platelet aggregation/agglutination. Aggregation/agglutination was diminished by 93 +/- 5% for collagen (0.2 mg/ml), 53 +/- 3% for thrombin (1.0 U/ml) and 85 +/- 9% for ristocetin (1.1 mg/ml). These data suggest that membrane fluidity is involved in the regulation of platelet function.
Vlasic
N
N
Department of Experimental Pathology, New York Medical College, Valhalla 10595.
Medow
M S
MS
Schwarz
S M
SM
Pritchard
K A
KA
Stemerman
M B
MB
D000371:Agglutination; D000818:Animals; D002417:Cattle; D005454:Fluorescence Polarization; D006801:Humans; D066298:In Vitro Techniques; D008560:Membrane Fluidity / Q000187:drug effects / Q000502:physiology*; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology*; D013228:Stearates / Q000494:pharmacology; D013997:Time Factors
D013228:Stearates; C023714:A(2)C