Fig. 8.
Depolarization induces multiple pro-PACAP mRNA levels. Regulation of cellular pro-PACAP mRNA expression was evaluated by Northern blot analysis. SCG neurons were incubated in medium containing 40 mm NaCl (−K+) or 40 mm KCl (+K+) for 96 hr beginning on day 9 of culture. Poly(A+) RNA was isolated from total RNA from 1.8 × 105 sympathetic neurons, separated on denaturing gels, transferred to a nylon membrane, and hybridized to a pro-PACAP-specific radiolabeled riboprobe. Representative autoradiograms are shown (n = 4). Hybridization to the pro-PACAP transcripts was examined at shorter (9 hr) and longer (114 hr) film exposure times. Two micrograms of poly(A+) mRNA from hypothalamus (Hypo) and testes were analyzed for pro-PACAP mRNA in parallel and exposed to film for 39 hr.