Effect of angiotensin II on t-PA and PAI-1 antigens in cultured human umbilical vein endothelial cells/

Objective: To investigate the effect of angiotensin Ⅱ (Ang Ⅱ ) on fibrinolytic activity of endothelial cells (EC). Methods: To quantify the total tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor - 1 (PAI - 1) antigens in human umbilical vein endothelial cell (HUVEC) -conditioned media by enzyme-linked irn-munosorbent assay (ELISA). The effect of various dose Ang Ⅱ on t-PA and PAI-1 secretion, and the effect of a given dose Ang Ⅱ incubated with EC for different periods on t-PA and PAI -1 secretion were observed. Results: After EC were incubated with various-dose Ang Ⅱ (10-10, 10-9, I0-8, l0-7and 10-6mol/L) for 4 hours, PAI-1 antigens in conditioned-media were (94.00±18. 62), (136.10±19.20), (164. 22±25. 60) , (188.00±122.36), (140.50± 25. 31 ) and (124. 48 ± 24. 20) ng (3×105) EC respectively, however, t-PA antigens remained no significant change; after EC were incubated with 10-8 mol/L Ang Ⅱ , PAI-1 antigens began to increase at 2 h, reaching peak (3.5 (imes) at 4 h compared with the corresponding control group. Conclusion; Ang Ⅱ (10-10-10-6mol/L) can increase PAI-1 antigens.