Abstract
The authors have reported an activation of platelets associated with an increase in plasma von Willebrand factor (vWF) level after isometric exercise in patients with ischemic heart disease (IHD). In this study, glass beads columns were employed as an experimental model to exclude the influence of vWF from intima of blood vessels.
MATERIALS and METHODS: 0.38% citrated blood samples obtained from 13 healthy subjects were filtrated through glass beads column (glass surface: 25cm2) two times with the column tenewed each time. Platelet count (Coulter Counter ZBI), platetet size (Coulter Channelyzer), platelet sensitivity to ADP-aggregation (Sano, et al.: Thrombos. Haemostas., 37: 329, 1977), plasma vWF level (Sano, et al.: Thrombos. Haemostas., 42: 1589, 1979 (Fig. 1) and plasma factor VIII related antigen (F VIII R:AG) (Partigen immunoplate) were measured before and after the filtrations.
RESULTS: Platelet count and size did not change significantly, while platelet sensitivity, vWF and F VIII R:AG increased significantly after filtration comparing to the non-filtrated original samples (Table 1, Fig. 2). The increments after the second filtrations comparing to the original values were significantly greater than the increments after the first filtrations.
CONCLUSION: An interaction between platelets and rough surface of glass beads indued an activation and release reaction of platelets in vitro.
This finding suggests the significance of such kind of interaction in the activation of platelets associated with release reaction in vivo, which was observed in IHD patients after isometric exercise.
