The role of Fbg in platelet adhesion to polymeric materials in conditions of psychological stress

The effect of psychological stress on platelet adhesion to five polymeric m aterials (polyurethane, polyurethane filled with BaSO4, polyethyleneterepht halate, silicone and low-density polyethylene) was studied. The platelets w ere obtained from non-stressed and stressed rabbits as platelet-rich plasma (PRP) and, once washed (Pw), were suspended in different media, i.e. in pl atelet poor plasma (Pw-PPP), in serum (Pw-S) and in Krebs-Ringer solution ( Pw-KR). Scanning electron microscopy of platelet adhesion and morphology re vealed differences in the platelet activating power of the various material s. The washing procedure and resuspension in PPP generally resulted in an i ncreased number of adherent platelets, compared with the number of platelet s adherent to the same material in PRP. However, platelets washed and suspe nded in Pw-KR or Pw-S showed the same shape distribution as in PRP. When pl atelets from stressed rabbits were used, there was very strong aggregation and activation of the platelets in both PRP and Pw-PPP, independent of the chemical nature and surface structure of the material. In contrast, in Pw-K R and Pw-S tin which Fbg is absent) a general picture of single, not very m odified platelets was observed. Their number and shapes changed according t o the nature of the different materials. On the whole, the present results confirm our original hypothesis of a key role of the psychological conditio n of the blood donor and strongly indicate Fbg as the determinant factor in the pattern of platelet adhesion. (C) 1999 Elsevier Science Ltd. All right s reserved.