Endogenous pituitary PACAP contributes to basal gonadotropin secretion and subunit mRNA expression levels. Pituitary cell monolayer cultures from E19, PN5, and PN15 male rats were incubated with various concentrations of PACAP 6-38 for 8 h, and the media were evaluated for LH (A) and FSH (B) secretion. C, Pituitary cell monolayer cultures from E19, PN5, and PN15 male rats were incubated in the presence or absence of 10 nm PACAP 6-38 for 8 h. Pituitary cell RNA was isolated and processed for qRT-PCR analyses of the gonadotropin subunit mRNA levels. The data are expressed as copies of gonadotropin subunit mRNAs per microgram total RNA. Each value (n = 3) represents the mean ± sem of three independent experiments, each performed in triplicate. Statistical analyses were performed with two-way ANOVA followed by pairwise comparison using TK-HSD≠ (A and B) or (C) by Student’s t tests. *, P < 0.05 vs. control.