Expression of the PAR-1 protein on the surface of platelets in patients with chronic peripheral arterial insufficiency - preliminary report.

Abstract

The activation of pro-coagulation mechanisms associated with the vascular wall's immune and inflammatory responses wall to injury plays a crucial role in the mechanisms of the induction and progression of atherosclerosis. The aim of this study was to determine the role of protease activated receptors (PAR-1) expressed on the surface of blood platelets in the pathogenesis of chronic peripheral arterial obliterative disease (PAOD) in patients with obliterative atherosclerosis (n = 24) and diabetic macroangiopathy (n = 16), as well as in the controls (n = 12). In addition to the expression of PAR-1, serum/plasma concentrations of thrombin-antithrombin complex (TAT), the von Willebrand factor (vWF), the platelet-derived growth factor, monocyte chemotactic protein, the soluble form of the platelet endothelial cell adhesion molecule, thrombin activatable fibrinolysis inhibitor and interleukin 6 (IL-6) were determined. Compared to the controls, PAOD patients were characterized by significantly higher levels of PAR-1 expression, vWF, TAT and IL-6. Individuals with diabetic macroangiopathy did not differ significantly from individuals with obliterative atherosclerosis in terms of PAR-1 expression. Upon activation with thrombin receptor antagonist peptide (TRAP), the levels of PAR-1 were comparable in all analyzed groups. In patients with diabetic macroangiopathy, a significant association was observed between the expression of PAR-1 on the surface of the platelet and the serum TAT concentration, as well as between TAT and serum IL-6 concentration. Enhanced expression of PAR-1 on the thrombocyte surface in chronic PAOD patients occurs equally in cases of diabetic macroangiopathy and in individuals free from this endocrine pathology.