Abstract: | The influences of experimental hypercholesterolemia in the rabbit on platelet-vessel wall interactions have been studied by evaluating the aggregatory response of platelet rich plasma (PRP) to arachidonic acid (AA) stimulation and levels of 6-keto-PGF1α in PRP from normal (N) and hypercholesterolemic (HC) animals prior and after perfusion through the corresponding aortas. In addition, the responses of N PRP to aggregation after perfusion through HC aortas and those of HC PRP perfused through N aortas, and the platelet response to the inhibitors effect of exogenous prostocyclin have been evaluated. The data indicate that in HC rabbits, on one side platelets aew hyperreactive to AA and less sensitive to the inhibitory activity of prostocyclin and, on the other, the antiaggregatory activity and prostacyclin production of vessel walls is higher, suggesting compensatory mechanisms in the haemostatic balance. |