Fig. 2.

Hypoxic HPASMC proliferation is mediated by reactive oxygen species (ROS). A: hypoxia-induced increased H₂O₂ production by HPASMC is inhibited by N-(2-mercaptopropionyl) glycine (MPG) and diphenyleneiodonium (DPI). Each condition represents the mean of 3 samples ± SD. *P < 0.001, 1% O₂ + MPG or DPI vs. 1% O₂ alone. B: scavenging of H₂O₂ by catalase prevents hypoxia-induced cell HPASMC proliferation. Results are representative of 3 independent experiments. *P < 0.05, 1.0% O₂ vs. 1.0% O₂ + catalase at 48 h. MTT, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide.