Plasma membrane properties in heterogeneous human blood platelet subfractions modulate the cellular response at the second messenger level.
Three subfractions of human blood platelets differing in density and function exhibited also differences when EPR (electron paramagnetic resonance) spin label measurements and fluorescence polarization were performed. The membrane anisotropy in the plasma membranes was higher in low density platelets as compared with that of platelets of intermediate and higher densities. This higher plasma membrane anisotropy correlated with a significantly higher cholesterol-phospholipid (C:P) molar ratio in the plasma membranes of low density platelets. As compared with the other platelet subfractions the low density platelets exhibited the smallest cAMP increase after activation with the aggregation inhibitor prostaglandin (PGE1), and the highest percentage of inositol phosphate accumulation after thrombin stimulation. The results suggest a high correlation between functional parameters and the plasma membrane architecture of human blood platelets.
Opper
C
C
Dept. Neurochemistry, Philipps University, Marburg, Germany.
Fett
C
C
Capito
B
B
Raha
S
S
Wesemann
W
W
D000262:Adenylyl Cyclases / Q000378:metabolism; D000527:Alprostadil / Q000494:pharmacology; D001792:Blood Platelets / Q000737:chemistry / Q000187:drug effects / Q000648:ultrastructure*; D002458:Cell Fractionation; D002499:Centrifugation, Density Gradient; D002784:Cholesterol / Q000032:analysis; D000242:Cyclic AMP / Q000502:physiology*; D004578:Electron Spin Resonance Spectroscopy; D004837:Epinephrine / Q000494:pharmacology; D005454:Fluorescence Polarization; D006801:Humans; D007295:Inositol Phosphates / Q000378:metabolism; D008563:Membrane Lipids / Q000737:chemistry* / Q000302:isolation & purification; D010743:Phospholipids / Q000032:analysis; D015290:Second Messenger Systems; D013347:Subcellular Fractions / Q000737:chemistry
D007295:Inositol Phosphates; D008563:Membrane Lipids; D010743:Phospholipids; D002784:Cholesterol; D000242:Cyclic AMP; D000262:Adenylyl Cyclases; D000527:Alprostadil; D004837:Epinephrine