Calcium influx through channels other than voltage-dependent calcium channels is critical to the pituitary adenylate cyclase-activating polypeptide-induced increase in excitability in guinea pig cardiac neurons

Abstract

Pituitary adenylate cyclase-activating polypeptide (PACAP) effects on intracellular calcium ([Ca ] ) and excitability have been studied in adult guinea pig intracardiac neurons. PACAP increased excitability, but did not elicit Ca release from intracellular stores. Exposure to a Ca -deficient solution did not deplete [Ca ] stores but did eliminate the PACAP-induced increase in excitability. We postulate that Ca influx is required for the PACAP-induced increase in excitability. © 2006 New York Academy of Sciences. 2+ 2+ 2+ 2+ 2+ i