Objective: To investigate the effects and mechanisms of amlodipine therapy on endothelium dysfunction induced by angiotensin-II (Ang-II) stimulation.
Methods: Human umbilical vein endothelial cells (HUVECs) were used and divided into five groups: Blank control, Ang-II (10(-6 )mol/L), levorotatory amlodipine (5 × 10(-6 )mol/L) + Ang-II (10(-6 )mol/L), dextrorotatory amlodipine (5 × 10(-6 )mol/L) + Ang-II (10(-6 )mol/L) and racemic amlodipine (5 × 10(-6 )mol/L) + Ang-II (10(-6 )mol/L) groups. Twenty-four hours later, HUVECs were collected for evaluating endothelial nitric oxide synthase (eNOS), p-eNOS, rho-associated kinase 1 (ROCK1), Bcl-2 and Bax expressions. Nitric oxide (NO) concentration within endothelium was also detected. Flow cytometry was conducted to assess HUVECs apoptosis.
Results: With 24 hours of Ang-II stimulation, compared to blank control group, expressions of eNOS and p-eNOS and NO production were significantly reduced in Ang-II group (p < 0.05), while adding amlodipine-protected HUVECs from dysfunction induced by Ang-II. In contrast, ROCK1 expression was promoted in Ang-II group (p < 0.05). However, the expression of ROCK1 in each enantiomer of amlodipine group was significantly decreased (p < 0.05). Compared to levorotatory amlodipine group, the magnitude of ROCK1 diminishment in dextrorotatory amlodipine group was more profound (p < 0.05). The pro-survival protein (Bcl-2) was significantly upregulated, while the pro-apoptotic protein (Bax) was significantly downregulated in three amlodipine groups compared to Ang-II group. Flow cytometry revealed that amlodipine therapy could protect HUVECs from apoptosis, and no significant difference between three amlodipine groups was observed.
Conclusion: Amlodipine could suppress Ang-II-induced endothelial dysfunction and apoptosis through diminishing ROCK1 expression.
Keywords: Rho-associated kinase; amlodipine; endothelial function.