ENDOTHELIAL ACTIVATION AND ENDOTHELIAL LEUKOCYTE INTERACTION IN HYPERTENSION

Endothelium plays a complex role in vascular biology: regulates blood vessel tone, haemostasis, neutrophil recruitment, hormone trafficking, and fluid filtration.Endothelial adherence and migration of leukocytes into tissue is mediated by different sets of adhesion molecules expressed on activated endothelial cells and their complementary ligands on leukocytes, such as ICAM-1:LFA1 pair, or VCAM-1:VLA4 pair.The expression of these molecules might not only preselect the types of leukocytes that enter the inflammatory sites, but also activate these leukocytes, induce adherence to epithelial cells, and cause the release of cytokines, leading to inflammatory response and endothelial damage, such as in atherosclerosis, lung diseases and diabetes mellitus. Our recent studies demonstrated significantly increased expression of certain subsets of endothelial cell adhesion molecules (eCAMs) accompanied with decrease in their ligands expression on circulating leukocytes in patients with untreated hypertension. Antihypertensive therapy, regardless of class of drugs used decreased blood pressure (BP) and modified the eCAMs expression, which positively correlate with BP while their ligands on circulating leukocytes inversely correlated with BP. In conclusion, increased BP is linked to endothelial activation and increased adherence of leukocytes to endothelium, which together with increased vascular oxidative stress contributes to endothelial damage and development of atherosclerotic lesions.