Ang-1, Ang-2, Tie-2, and GAPDH by RT-PCR from HEECs and HESCs RNA. Total RNA was extracted from untreated HEECs or HESCs treated with E2 (E), MPA (P), or E2 + MPA (E + P) and semiquantitative RT-PCR was conducted as described in Materials and Methods. The bottom panel shows the corresponding HESC and HEEC RNA in which reverse transcriptase was excluded from the reaction mixture. The primers used for this negative control reflect those of GAPDH (GAP). Similarly, no product was observed when reverse transcriptase was omitted and the reaction was performed with primers for Ang-1, Ang-2, or Tie-2 (not shown).