PACAP activates PKA, PKC and Ca2+ signaling cascades in rat neuroepithelial cells

Several studies have reported that the PAC, receptor (PAC1-R), the specific receptor for PACAP, is expressed at early developmental stages. Here, we d escribe that the cytosolic Ca2+ concentration ([Ca2+](i)) was increased by PACAP, but not VIP, in a concentration range from 10(-12) to 10(-8) M via t he PAC(1)-R in isolated single cells from the rat neural fold. This activat ion of the cells by PACAP was mimicked by agonists and inhibited by antagon ists of the cAMP/PKA and PLC/PKC cascades. These data indicate that PACAP/P AC(1)-R is linked to [Ca2+](i) signaling via two G-protein-coupled protein kinase pathways and may thereby play an important role in early neurodevelo pment. (C) 2001 Elsevier Science Inc. All rights reserved.