Fig. 6

Time course of Ang-1 and Ang-2 mRNA remaining in villi obtained at term relative to β-actin following treatment with actinomycin D. Villous explants were cultured with actinomycin D for 0, 2, 4, and 8 hr under ambient and reduced oxygen conditions. RNA extraction and semiquantitative RT-PCR were performed as described in the Material and Methods. The stability of Ang-1 mRNA decreased under reduced oxygen and it was below the sensitivity of this method of detection after 4 hr culture in the presence of actinomycin D. Ang-2 mRNA had a similar decay rate under ambient and reduced oxygen conditions, indicating that the increased Ang-2 mRNA detected under reduced oxygen was due to increased transcription. β-actin mRNA levels do not change under varying oxygen conditions. Data are presented as mean ⩲ SEM. Experiments at each time point were performed in triplicate. ❍ ambient oxygen; ■ reduced oxygen; × detection below the sensitivity of this method.