PACAP in avians: origin, occurrence, and receptors--pharmacological and functional considerations.
Pituitary adenylate cyclase-activating polypeptide (PACAP) is a novel member of the secretin/glucagon/vasoactive intestinal peptide (VIP) superfamily. In vertebrates, including avians, it occurs in two forms: PACAP(38) and PACAP(27). PACAP structure is well conserved during evolution, being identical in mammals, and showing one amino acid dfifference in avians (chick, turkey). PACAP is widely distributed in the central nervous system and peripheral tissues and displays a pleiotropic activity, including functions as a hypophysiotropic hormone, neuromodulator, and neurotrophic factor. PACAP exerts its biological actions through three types of receptors designated PAC(1), VPAC(1) and VPAC(1). This review (1) presents the current knowledge on PACAP origin, distribution and function, (2) compares the avian findings with those found in mammals, and (3) describes receptor-linked mechanisms in avians, including recent data on receptor-related signal transduction pathways, with a special emphasis on receptor pharmacology and function.
Nowak
Jerzy Z
JZ
Department of Biogenic Amines, Polish Academy of Sciences, Lodz, Poland. jerzyn@amina1.zabpan.lodz.pl
Zawilska
Jolanta B
JB
D000595:Amino Acid Sequence; D000818:Animals; D001717:Birds / Q000502:physiology*; D001921:Brain / Q000502:physiology; D019143:Evolution, Molecular; D009479:Neuropeptides / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000737:chemistry / Q000502:physiology*; D017933:Peripheral Nervous System / Q000502:physiology; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011487:Protein Conformation; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D011979:Receptors, Pituitary Hormone / Q000145:classification / Q000502:physiology; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction / Q000502:physiology; D014018:Tissue Distribution
D009479:Neuropeptides; D018377:Neurotransmitter Agents; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D011979:Receptors, Pituitary Hormone