Effect of 8-Br-cAMP and CRH on hCG secretion. BeWo cells were cultured in 10% CCS media and treated with or without 50~100 μM 8-Br-cAMP (A) or 10~100 nM CRH (B) for 72 h. The amount of hCG in the media was measured by ELISA assay. The respective cell number was determined by MTT assay. The relative amount of hCG secretion was normalized by the cell number. Results shown are the induction fold relative to the control which was set at 1.0. Values are mean ± S.D. from 3 independent experiments. * p<0.05.