Western blot analysis detecting HIF-1α and GAPDH (loading control) in lysates of BSMC.

<p>Cells were incubated under 1% and 21% O₂ for 4, 24 and 48 h (indicated at top). CoCl₂ was used as positive control to stabilize HIF-1α protein. In contrast to CoCl₂, which has a transient effect only, hypoxia induced a prolonged expression of HIF-1α. The experiments shown are representative for 5 independent experiments. The right hand panel (showing the 24 h and 48 h expression levels of HIF-1α) was obtained after longer exposure of the same blot, which contained all samples.