PAC1 receptors in chick cerebral cortex: characterization by binding of pituitary adenylate cyclase-activating polypeptide, [125I]-PACAP27.
In this study we characterized receptors for pituitary adenylate cyclase-activating polypeptide (PACAP) in chick cerebral cortex by in vitro binding technique, using [125I]-PACAP27 as a ligand. The specific binding of [125I]-PACAP27 to chick cerebral cortical membranes was found to be rapid, stable, saturable, and of high affinity. Scatchard analysis suggested binding to a single class of receptor binding sites with high affinity (K(d)=0.41+/-0.08 nM) and high capacity (B(max)=457+/-35 fmol/mg protein). The relative rank order of potency of the tested peptides to inhibit [125I]-PACAP27 binding to chick cerebrum was: PACAP38 approximately PACAP27>PACAP6-27 approximately PACAP6-38 >> chicken VIP >> mammalian VIP >> secretin (inactive). It is concluded that the cerebral cortex of chick, in addition to VPAC recognition sites, contains a large population of PAC(1)-type receptor binding sites.
Zawilska
Jolanta B
JB
Department of Biogenic Amines, Polish Academy of Sciences, Institute of Biogenic Amines, P.O. Box-225, 90-950, Lodz, Poland. jolantaz@anima1.zabpan.lodz.pl
Niewiadomski
Pawel
P
Nowak
Jerzy Z
JZ
D000818:Animals; D000831:Animals, Newborn; D001665:Binding Sites; D002540:Cerebral Cortex / Q000378:metabolism*; D002645:Chickens; D066298:In Vitro Techniques; D007457:Iodine Radioisotopes; D008024:Ligands; D008297:Male; D008566:Membranes; D009479:Neuropeptides / Q000378:metabolism*; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011869:Radioligand Assay; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D051237:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; D011979:Receptors, Pituitary Hormone / Q000378:metabolism*
D007457:Iodine Radioisotopes; D008024:Ligands; D009479:Neuropeptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D051236:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide; D051237:Receptors, Pituitary Adenylate Cyclase-Activating Polypeptide, Type I; D011979:Receptors, Pituitary Hormone