**2. Endothelial cell function**

Vascular endothelium is crucial for the regulation of vascular homeostasis. It is metabolically active through the secretion of vasodilators and vasoconstrictors and acts as an active signal transducer for circulating factors that modify the vessel wall phenotype. The normal paracrine and autocrine functions of endothelial cells include the synthesis of a series of substances that moderate vascular tone, decrease leucocyte migration, control permeability, regulate proliferation and migration of smooth muscle cells, and regulate platelet adhesion and aggregation (**Figure 1**). Endothelium also regulates cellular adhesion, vessel wall inflammation, and angiogenesis.

The mechanisms implicated in the genesis of endothelial dysfunction are of extreme importance in developing adequate strategies to prevent or retard the clinical manifestations of cardiovascular diseases.
