Fig. 1.

PACAP-27 upregulation of VIP peptide and mRNA levels in comparison to stimulation of protein kinase C, elevation of cAMP, and depolarization. A, VIP peptide upregulation by treatment with PACAP, PMA, KCl, or forskolin at 24 and 72 hr. Drug treatments were performed as described in Materials and Methods, with cells and medium harvested for VIP radioimmunoassay after 24 and 72 hr exposure to 100 nm PACAP, 100 nm PMA, 40 mm KCl, or 25 μm forskolin (FOR). Values represent the mean ± SEM of quadruplicate wells from a single cell dispersion, repeated at least once with similar results. *Different from control at corresponding time; p < 0.001; Scheffe's post hoc analysis. B, VIP mRNA levels after treatment with 100 nm PACAP, 100 nm PMA, 40 mm KCl, or 25 μm forskolin. Drug treatments were performed as described for peptide induction, except that cells were harvested for RNA isolation and Northern blotting as described in Materials and Methods 18 hr after drug addition. Equal well-equivalents of total RNA were added to each lane. The single experiment shown was repeated twice with similar results. C, Quantitative PCR for VIP mRNA after treatment with 100 nm PACAP, 40 mm KCl, or 25 μm forskolin. Cells were harvested for quantitative RT-PCR at 18–24 hr after treatment as described in Materials and Methods. Values represent the mean ± SEM of quadruplicate wells from a single cell dispersion, repeated at least once with similar results. *Different from control;p < 0.001; Scheffe's post hocanalysis.