PACAP, VIP, and PHI
Pituitary adenylate cyclase-activating polypeptide (PACAP), vasoactive intestinal peptide (VIP), and peptide histidine-isoleucine (PHI) are members of a superfamily of structurally related peptides widely distributed in the body and displaying pleiotropic biological activities. All these peptides are known to act via common receptorsVPAC1 and VPAC2. In addition, the effects of PACAP are mediated through its specific receptor named PAC1. The main signal transduction pathway of the mentioned receptors is adenylyl cyclase (AC)cAMP system. PACAP and VIP may also signal through receptor-linked phospholipase C (PLC)IP3/DAGPKC and phospholipase D (PLD)phosphatidic acid (PA) pathways. In the present article, we have studied the effects of PACAP, VIP, and PHI (0.0015000 nM) on the AC-, PLC-, and PLD-driven signaling pathways in rat primary glial cell (astrocytes) cultures. All tested peptides dose-dependently and strongly stimulated cyclic adenosine 3,5-monophosphate (cAMP) production in this experimental model, displaying the following rank order of potenc
pituitary adenylate cyclase-activating polypeptide (pacap) vasoactive intestinal peptide (vip) peptide histidineisoleucine (phi) cyclic amp (camp) phospholipase c (plc) phospholipase d (pld) primary glial cell cultures