Figure 7

Effect of β-AR stimulation on VEGF-A expression and VEGFR-2 activation in HemECs. A, HemECs were pre-treated with MET (10 μM), ICI (10 μM) or U0126 (1 μM) for 1 h and incubated with ISO (1 μM) for 12 h. The expression of VEGF was then measured. GAPDH was used as an internal control. B, HemECs were treated with ISO for various times (0-20 h), and the phosphorylation level of VEGFR-2 was detected by Western blot using a phospho-specific antibody against the VEGFR-2 Tyr1175 residue. The ISO-induced phosphorylation of VEGFR-2 at Tyr1175 followed a bell-shaped curve starting at 1 h, reached a peak at 3 h and declined to basal levels after 15 h of treatment. C, HemECs were pre-treated with MET (10 μM), ICI (10 μM) or 2 μg/ml of a VEGF neutralizing antibody (VEGF Ab) for 1 h before incubating the cells with ISO (1 μM) for 3 h. The phosphorylation status of VEGFR-2 was then detected. B and C denote the mean ± SD of three experiments for each condition and was determined by the densitometry values that were determined relative to the total amounts of VEGFR-2. * P<0.05 when compared with the ISO-untreated control, ^† P<0.05 when compared with the ISO-treated control.