Figure 1.

Hypoxia increases the proliferation and cell cycle progression of pulmonary arterial smooth muscle cells (PASMCs). (A) PASMCs were seeded at 1 × 10⁴ cells/well (0.1 ml) in 96-well flat-bottomed plates and incubated overnight at 37°C. After exposure to hypoxia (1% oxygen) and normoxia chamber, respectively, for 6, 12, 24 and 48 hrs, cell proliferation was measured by 5-bromo-2′-deoxyuridine (BrdU) incorporation. The values are mean ± SD,n = 5. (B) Cell migration of PASMCs under hypoxia condition at 24 hrs by transwell assays. Columns represent the mean of three individual experiments performed in triplicate. *P < 0.05 versus normoxia group. (C) Cell cycle analysis of PASMCs in hypoxia condition at 24 hrs by flow cytometry. The results were expressed as relative cell growth in percentage, which was compared with a 21% oxygen control group. The concentration of 21% oxygen was set as control. n = 5 for each group. *P < 0.05 versus normoxia group.