[Binding of low density lipoproteins (LDL) to platelets]

Binding of LDL to platelets was studied by two independent methods, radioactive and flow cytofluorimetry, using 125I- and fluorescently labelled RITC-LDL. Saturation of 125I- and RITC-LDL binding to platelets, inhibition of binding by unlabelled LDL and a lower inhibitory effect of unlabelled HDL evidence the existence of a limited number of binding sites specific for LDL in platelets. Unlike nuclear cells platelets do not degrade LDL. The binding of LDL to platelets is reversible and independent of Ca2+. The decrease of total binding level at 4 degrees and the absence of heparin effect on the release of bound LDL suggest LDL incorporation into platelets.