Figure 2.

Role of β-ARs in the proliferation of HemECs. A, Incubation of HemECs with ISO for 12 h increased DNA synthesis in a dose-dependent manner with an EC₅₀ of 340 ± 41 nM. HemECs were incubated in EBM-2 with 5% FBS and synchronized for 24 h in EBM-2 with 0.1% BSA prior to stimulation. B, HemECs were incubated in the presence of 1 μM ISO for various times (0-36 h). C, The effects of β₁- and β₂-AR blockade with MET and ICI on ISO-induced HemECs proliferation. HemECs were pre-treated with MET or ICI for 1 h followed by the addition of 1 μM ISO. ICI more efficiently blocked ISO-enhanced cell proliferation. D, The number of viable cells was counted using CCK-8. ISO treatment increased cell number, whereas MET and ICI prevented the ISO-induced increase in cell number. The results are shown as the mean ± SD of triplicate assay from one of three identical experiments. * P<0.05 when compared with the ISO-untreated control, ^†P<0.05 when compared with the ISO-treated control, ^#P<0.05 when compared with the MET-treated group.