Figure 4.

Expression of pituitary adenylate cyclase-activating polypeptide (PACAP; A), PACAP receptor (PAC1; B), gonadotropin-releasing hormone receptor (GnRHR; C), and progesterone receptors (PRB; D) in rat pituitary cells treated with estradiol (E₂). PRB messenger RNA (mRNA) expression was used as positive controls for E₂ treatment. The cells were treated with vehicle, 10, or 100 nmol/L E₂ for 6 or 24 hours. Samples were analyzed as described in Figure 1. Bars represent the mean ± standard error of the mean of each group (n ≥ 3). Bars at the same time point with different letters vary significantly (P < .05).