RESUMEN
OBJECTIVE: To determine the effects of fluorides on endothelial functioning. MATERIALS AND METHODS: We analyzed expressions of adhesion molecules, ICAM-1 and ICAM-3, and annexin V, on the surface of human umbilical vein endothelial cells (HUVECs) exposed to various concentrations of NaF and SnF(2) . We compared the effects of fluoride-induced changes with those obtained when stimulating HUVECs with TNF-α and verified whether N-acetyl cysteine (NAC), well-known antioxidant, can prevent both fluoride- and TNF-α-induced alterations. RESULTS: The expressions of annexin V and ICAM-1 increased significantly after adding NaF (5.0 or 7.5mM) or Sn(2) F (0.5 or 0.75mM) to the culture medium. Pre-incubating HUVECs with NAC prevented the effects induced by 5.0 mM of NaF and 0.5 mM of Sn(2) F. Only the highest concentration of NaF (7.5mM) triggered the expression of ICAM-3. The expressions of all three molecules increased significantly upon stimulating the cultures with TNF-α (20ng ml(-1) ); these changes were not reversed by pre-incubation with NAC. CONCLUSIONS: Fluorides induce oxidative stress, resulting in apoptosis and activation of HUVECs, manifested by an elevated expression of ICAM-1. The oxidative stress resulting from a stimulation by the highest NaF concentration triggers ICAM-3 expression on the HUVECs' surface.
