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.
Pituitary adenylate cyclase-activating polypeptide (PACAP) effects on intracellular calcium ([Ca2+]i) and excitability have been studied in adult guinea pig intracardiac neurons. PACAP increased excitability, but did not elicit Ca2+ release from intracellular stores. Exposure to a Ca2+-deficient solution did not deplete [Ca2+]i stores but did eliminate the PACAP-induced increase in excitability. We postulate that Ca2+ influx is required for the PACAP-induced increase in excitability.
Hardwick
Jean C
JC
Department of Biology, Ithaca College, Ithaca, NY 14850, USA.
Tompkins
John D
JD
Locknar
Sarah A
SA
Merriam
Laura A
LA
Young
Beth A
BA
Parsons
Rodney L
RL
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects*; D015640:Ion Channel Gating; D007473:Ion Channels / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D009474:Neurons / Q000187:drug effects* / Q000378:metabolism*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide / Q000494:pharmacology*
D007473:Ion Channels; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D002118:Calcium