<P>Under physiological conditions, peripheral arteries release endogenous vascular-protective and antithrombotic
agents. Endothelial cells actively synthesize vasoactive mediators, which regulate vascular tone and
platelet reactivity thus preventing thrombosis. Atherosclerosis disrupts homeostasis and favours thrombosis by
triggering pro-thrombotic responses in the vessels, platelet activation, aggregation as well as vasoconstriction,
phenomena that ultimately lead to symptomatic lumen restriction or complete occlusion.
<P>
In the present review, we will discuss the homeostatic role of arterial vessels in releasing vascular-protective
agents, such as nitric oxide and prostacyclin, the role of pro- and anti-thrombotic vascular receptors as well as
the contribution of circulating platelets and coagulation factors in triggering the pro-thrombotic response(s). We
will discuss the pathological consequences of disrupting the protective pathways in the arteries and the pharmacological
interventions along these pathways.</P>
