Fig. 5.

hCG expression by estradiol and neuropeptides. Primary cultures of rat placental cells were cultured in the presence or absence (control) of estradiol (E2) (a), kisspeptin (100 nM), GnRH (100 nM), or NKB (100 nM) (b) for 24 h. Then, hCG mRNA levels were measured by quantitative real-time PCR after mRNA extraction and reverse transcription. Samples for each experimental group were run in duplicate and normalized to GAPDH mRNA levels as a housekeeping gene. Results are expressed as fold stimulation over the unstimulated group/control. Values are the mean ± SEM of fold stimulation taken from independent experiments. **P < 0.01, *P < 0.05 vs. control