T. Sugiura et al., BIOCHEMICAL-CHARACTERIZATION OF THE INTERACTION OF LIPID PHOSPHORIC-ACIDS WITH HUMAN PLATELETS - COMPARISON WITH PLATELET-ACTIVATING-FACTOR, Archives of biochemistry and biophysics, 311(2), 1994, pp. 358-368
A series of lipid phosphoric acids, including 1-O-alkyl-2-lyso-glycero
phosphoric acid, 1-O-acyl-2-lyso-glycerophosphoric acid, hexadecylprop
anediolphosphoric acid, N-acyl-2-aminoethanolphosphoric acid, sphingos
ine phosphoric acid, and certain homologues and analogues, were synthe
sized and characterized by thin-layer chromatography, fast-atom bombar
dment mass spectrometry, and their ability to aggregate human platelet
s. The presence of a receptor for these lipid phosphoric acids that is
distinct from the PAF receptor is strongly suggested from experiments
involving a desensitization procedure, platelet-activating factor (PA
F) receptor antagonists, and inhibitors of the lipid phosphoric acids.
The unique features of the interaction of these lipid phosphoric acid
s with platelets include: (a) evidence for a separate receptor(s) for
this diverse group of synthetic compounds, (b) no requirement for ster
eospecificity (i.e., no glycerol backbone), and (c) a structural requi
rement for a long-chain hydrocarbon residue covalently bound to a phos
phoric acid residue. In the interaction of these compounds with the pl
atelet, it is mandatory that extracellular Ca2+ and ADP be present for
maximum biological activity. The potential involvement of a lipid pho
sphoric acid receptor, which could form a component of the activation
pathway associated with various lysophospholipids and analogues, such
as PAF, via a phospholipase D activation, is discussed.(C) 1994 Academ
ic Press, Inc.