Fig. 1. Effects of propofol on strain-induced endothelin-1 (ET-1) expression. ( A ) Propofol inhibits strain-induced ET-1 mRNA expression. Human umbilical vein endothelial cells (HUVECs) were either vehicle controls (C, lane 1), or treated with different concentrations of propofol (1–30 μm) in the absence (lanes 2–5) or the presence of strain treatment (lanes 6–10) for 6 h. Total RNA was extracted and Northern hybridization was performed with 32P-labeled ET-1 as the probe. 18S RNA was used to normalize the RNA applied in each lane. Data are presented as percentage changes of experimental groups, as compared with untreated controls. ( B ) Propofol inhibits strain-induced ET-1 secretion. HUVECs were treated with propofol (1–30 μm) in the absence or the presence of strain treatment. After strain (20%) for 24 h, the culture media were collected and the concentrations analyzed by enzyme immunoassay. Results are presented as mean ± SEM (n = 6). * P < 0.05 versus unstrained control cells. # P < 0.05 versus strained cells (analysis of variance [ANOVA]).