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Aims:Angiotensin II (Ang II) causes endothelial cell damage. Oxidative stress is involved in the pathophysiology of cardiovascular diseases via transforming growth factor-beta 1 (TGF-β1). In most studies increases in Ang II and TGF-β1 levels in several cell types are bidirectional. The present study investigated the effects of Ang II on oxidative stress, cell proliferation, and TGF-β1 levels in human umbilical vein endothelial cells (HUVECs).Methods:HUVECs were treated with Ang II (0.1 μM), Ang II type 1 receptor (ATR1) antagonist Olmesartan (1 μM), and Ang II type 2 receptors (ATR2) antagonist PD123319 (1 μM) for 24 hours. Cell proliferation and viability were evaluated by the tetrazolium salt (MTT) assay. Total antioxidant capacity (TAC) and total oxidant capacity (TOC) were measured by spectrophotometer intracellularly and in the culture medium. The TGF-β1 level was measured by enzyme-linked immunosorbent assay (ELISA).Results:The addition of 1 μM, 0.1 μM, and 0.01 μM Ang II increased proliferation in HUVECs. Cell proliferation increased significantly in both Ang II and Ang II+Olmesartan+PD123319 groups. However, Ang II+Olmesartan tended to decrease cell proliferation. In the control group TAC and TOC levels remained in the normal range in HUVEC extracts. In other all groups, TOC values increased compared to control. In HUVECs medium, TAC level was higher in the control, Ang II and Ang II+Olmesartan groups, but normal and tolerable in other groups whereas, TOC levels were elevated in control and other all groups. In HUVECs extracts, compared with the control, TGF-β1 level was significantly lower in the Ang II group, but increased in the Ang II+Olmesartan group. There was no significant difference in TGF-β1 levels between medium groups.Conclusions:Ang II shows its proliferative effects through ATR1 activation, whereas stimulation of ATR2 seems to have a key role in the pathophysiology of oxidative stress. |
