Platelet function in a strain of rabbits designated as Watanabe heritable hyperlipidemic (WHHL) rabbits was examined. When compared to normolipidemic rabbits, the platelet aggregation induced by ADP and collagen were significantly higher in WHHL rabbits (P<0.01 or 0.05). Furthermore, platelet sensitivity for ADP was significantly higher in WHHL rabbits than in normolipidemic rabbits (P<0.01). The platelet aggregation among resuspended platelet in normolipidemic rabbit plasma was singnificantly higher in WHHL rabbits than in the normolipidemic rabbits (P<0.01). Furthermore, the botrocetin induced platelet agglutination (BIPA) as von Willebrand factor (vWF) activity was significantly higher in WHHL rabbits than in normolipidemic rabbits (P<0.01). As for change of platelet function with aging, the platelet aggregation induced by ADP increased with age and the BIPA were higher in WHHL rabbits than control rabbits at almost all ages and decreased between 5 and 8 months of age. These findings suggest that increased platelet function and vWF activity in WHHL rabbits are associated with the thrombotic complications and accelerated atherogenesis of WHHL rabbits.
